iPhone 6 vs iPhone 6S - should you upgrade?

Apple's smartphone upgrade cycle always takes in two models that use the same body, with the newer model getting new internals. We're at the end of one cycle now with the iPhone 6S and iPhone 6S Plus looking like their predecessors, the iPhone 6 and the iPhone 6 Plus. One of the big questions is, should you upgrade to one of the 6S models or should you wait for the iPhone 7 instead?

That's what Expert Reviews is here to answer. Now that I've had a chance to review all of the handsets, I can help you make the right decisions. Where relevant, I've made it clear when I'm talking about the Plus models specifically, but all other comments apply to both models in the range.

Design

Dimensions: Surprisingly, there are some differences between the regular 6 and 6S models, although you'd have to have the best eyesight and senses to tell that from looking at them. First, I'll take the smaller handset. While the iPhone 6 measures 138x67x6.9mm and weighs 129g, the iPhone 6S measures 138x67x7.1mm and weighs 143g. It's a similar story with the larger handsets, and the iPhone 6 Plus measures 158x78x7.1mm and weighs 172g, and the iPhone P6 Plus measures 158x78x7.3mm and weighs 192g. As you can see, the new phones are a fraction thicker than the previous models, and they weigh a little more. I'll explain the reasons for the differences below, although the main thing to point out is that the changes don't make any difference day-to-day and you won't perceptibly be able to detect the changes. 

In in terms of usability, the iPhone 6S Plus remains a large phone that won't suit some people. Personally, after more than a year of using Plus versions, I have to say that I'm completely used to the handset and wouldn't now want anything smaller. For everyone else, the iPhone 6S is a great size that fits easily in one hand and neatly balances screen size against physical size.

Materials: Both new and older handsets are built using a curved glass front screen (ION strengthened to prevent scratches) and aluminium bodies. For the 6S editions, Apple has used higher-quality and stronger aluminium, which helps explain a bit of the weight change. It also means that the new iPhones will be slightly tougher than the old ones. More cynical people will say that this is because the original iPhone 6 Plus could be bent (bendgate), but I think it's important to point out that this only happened if undue pressure was put on the handset and there weren't that many cases. Why make the new phone stronger, then? Well, the simple answer is, why not? Tougher phones are better all round. So, while the old phones are tough, the new ones are tougher. It's not enough to make a difference when choosing a handset, though.

Colours: The iPhone 6S and iPhone 6S Plus get one additional colour, Rose Gold, adding to the Gold, Silver and SpaceGrey editions. It's quite a nice shade and rather subtle. Now the iPhone and Apple Watch range are available in the same colours.  

Design conclusion: Unless you absolutely have to have an iPhone in Rose Gold, there's nothing between the 6 and 6S models, bar the new one's tougher build. Both phones remain exceptionally well made and, in my opinion, some of the most attractive handsets available.

Display

Screen size: The iPhone 6 and 6S both have a 4.7in screen. This is a good compromise between screen size and physical phone size and strikes the right balance for most people. The iPhone 6 Plus and 6S Plus both have a 5.5in screen, which is large. I love this screen size, as it's part way between a regular handset and a tablet, although appreciate that it's too big for some people. 

Should you not be able to use the phones one-handed, they all have Reachability. This control, introduced with the iPhone 6, is activated by double-tapping the TouchID button and makes the entire screen slide down to the lower half of the display, so you'll always have the top of the screen within reach at all times. You don't need to use this feature very often, as most of the screen is within easy reach of a thumb, but for those occasional times that you need it Reachability does a useful job.

Screen resolution and technology: The iPhone 6 and iPhone 6S have a 1,334x750 resolution, which is 326PPI. Both screens have the same image quality and sharpness. That's to say that both smartphones have excellent image quality. Given the competition, I'd like a bit more resolution, but there's nothing wrong with what's here.

In comparison, the iPhone 6 Plus and 6S Plus have a resolution of 1,920x1,080, which gives a pixel density of 401PPI. I like the extra resolution and screen sharpness over the regular iPhone models. I have to say that competitor smartphones with more resolution don't look a lot sharper. Image quality from the IPS screen hasn't changed between models. Both of the Plus models have additional landscape modes (a home screen and better mailbox view, for example) than the regular models.

3D Touch: What the new iPhone models give you is 3D touch, which requires an extra sensor to detect pressure to be installed under the screen (again, this helps explain the thicker body and extra weight). 3D Touch can detect two additional levels of pressure on the screen. For example, in the Mail app you can press hard to Peek at an email, with it popping up in a window; pressing harder again Pops you into the message proper. 3D Touch is also used on the home screen, too: press the Phone icon and you get a menu with your favourites on it, the Camera icon gives you shortcuts to common modes, and so on. It's really a very different and more intuitive way of using the iPhone and is something that no other phone has.

Display conclusion: 3D Touch is one of the best features to hit a smartphone in recent years and, if you want it, you need to buy one of the new 6S models to get it. Other than that, screen quality and sharpness remains the same between the handsets.

Performance

Processor: The iPhone 6 and 6 Plus have one of Apple's 64-bit A8 chips. This dual-core chip is extremely fast, keeping up with the current Android competition. As an example, the A8 scored 2,588 in the Peacekeeper browser test, which remains one of the best scores that we've seen. With the 6S and 6S Plus, you get the new A9 chip. This is even faster and scored an incredible 4,620 in Peacekeeper. It's the fastest mobile chip that we've ever seen.

Battery: Apple has reduced the size of the battery in the 6S models, in order to make way for the 3D Touch screen. So, the iPhone 6 had a 1,810mAh battery, but the iPhone 6S has a 1,715mAh battery; the iPhone 6 Plus has a 2,750mAh battery, but the 6S Plus has a 2,915mAh battery. In part, the more efficient A9 chip balances out the reduce battery size, and the Plus models lasted just shy of 15h in our video playback battery test. There was a bigger difference with the iPhone 6, which lasted 12h 58m, while the 6S lasted over an hour less. I have to point out that our battery test has the screen on all of the time; in day-to-day use, where the phone's synchronising in the background, the 6S models sip power thanks to the efficient processor and last longer.

Storage: All models are available in 16GB, 64GB and 128GB models. Strangely there's no 32GB version, and the phone doesn't support microSD cards either. I suggest buying the 64GB model as a minimum, as 16GB really is too small.

Performance conclusion: Raw CPU and graphical performance is better on the iPhone 6S, but not so much so that an upgrade is worthwhile. Day-to-day battery life remains the same, too, although in continuous use the new 6S lasts less time than the 6 did in our tests.

Camera

The iPhone 6 and 6 Plus have an 8-megapixel camera, while the 6S models have 12-megapixel sensors. What difference does that make? Well, it makes no difference to exposure quality or noise, as both sensors deal with most lighting situations extremely well and are, quality wise, some of the best smartphone cameras. Extra resolution means more detail in photos, as you can see by comparing the iPhone 6 Plus (top) and iPhone 6S Plus (bottom) sample shots.

More resolution also means that the newer iPhones can shoot 4K video, and the slow-motion mode now takes in Full HD at 120fps, as well as the 720p 240fps mode on the iPhone 6 models. Live Photos are new on the iPhone 6S models. This mode records 1.5 seconds of video before and after you take a shot at 15fps. When you press on the photo the video kicks into life and brings your photo alive adding context to it. I really like this mode, although I admit that getting perfect results isn't always easy; fortunately, if the video's no good, you can ditch it in the Edit mode and leave just the photo.

The dual-LED flash remains brilliant in all models, while the 6S and 6S Plus's screens can now use the screen for Retina flash. This matches the ambient light colour of where you are, so you can take selfies in the dark while still looking natural. Combined with the new 5-megapixel cameras on the front, up from 1.2-megapixels on the 6 models, selfies have never looked better.

Camera conclusion: There's little in it in terms of exposure and noise, but the higher-resolution sensors in the new models and extra shooting modes mean that the 6S and 6S Plus are superior.

Features

Touch ID and Apple Pay: All of the phones have Touch ID fingerprint readers built into the home buttons. This allows the phones to be unlocked with a finger, while apps that support the technology can use your fingerprint rather than you having to enter a password. As all of the phones have an NFC chip they can be used with Touch ID to use Apple Pay to pay for goods in a store. The only real difference between the 6 models and 6S models' fingerprint sensors, is that the latter's is newer, more accurate and quicker: I found that I could unlock my 6S Plus much faster than I could my 6. Admittedly, it's a minor improvement.

Siri: While all of the phones have the voice assistant, Siri, built in, the new models, thanks to the A9 chip can always listen for the phrase, 'Hey Siri'. This means that you can use Siri without touching your phone or unlocking it. Again, it's a minor improvement, but one that's quite useful: I often set reminders or get the latest weather report without having to touch my phone.

Features conclusion: Both new and old iPhones are extremely well featured. The new models have the slight edge with the improved Touch ID sensor and always-on Siri, and both are excellent additions to the handsets; however, it's not quite enough to suggest that you upgrade.

Wireless: The iPhone 6S and 6S Plus have upgraded wireless components, including faster 802.11ac networking (the 6 models have slower 802.11ac) and faster 4G. You need supporting networks to achieve the faster speeds, but they can make a difference: I can now get my broadband's full ~74Mbit/s download speed from my phone, whereas my old phone used to top out at around 55Mbit/s.

Features conclusion: As you'd expect from Apple's latest phones, they've got newer and faster components and improved features. Again, there's not quite enough here to make the upgrade a must-have.

Operating System

All of the phones now support iOS 9, the latest version of Apple's mobile operating system. Largely, the phones support the same range of features with only a couple of minor differences. For example, the iPhone 6S and 6S Plus let you hard press on the keyboard to turn it into a touchpad, letting you more accurately move the cursor around. Other than that there's not a lot between the two phones.

Conclusion

While the iPhone 6S and iPhone 6S Plus are undoubtedly improved phones, the truth is that we're not seeing the same year-on-year improvements that we were a year or so ago. In real terms, that means that if you've got an iPhone 6 or 6 Plus there's not enough with the new models to make it worth upgrading. If you absolutely have to have the latest model, then 3D Touch, an improved camera and super-fast processor at least mean that you have something different. If you've got an iPhone 5S or older, you'll get a massive improvement. Even then, you have a bit of a dilemma: should you save money and get the iPhone 6 or 6 Plus (both still excellent phones) or go the whole hog and buy one of the 6S models instead? I'd recommend the newer phones if you want to upgrade now, as 3D Touch and the better camera really make a noticeable difference.

Specifications - iPhone 6 vs iPhone 6S

Specifications - iPhone 6 Plus vs iPhone 6S Plus