 It's September, which means it's time to review a new iPhone. And because it's an S year for the iPhone, we're going to have to look a little bit deeper for changes. But that's okay. It turns out that these new phones are all about going deeper. This is the iPhone 6S. And this is the iPhone 6S Plus. Surprise! They look just like the iPhone 6 and the iPhone 6 Plus. Let's just get this out there. I think if you're buying an iPhone, you should buy the bigger 6S Plus. It's clear that phones with bigger screens are going to dominate the market, and you get a slightly better camera and battery life to boot. So it's actually really hard to review the iPhone 6S and the 6S Plus. It's the iPhone. Apple sales are skyrocketing. All these people around me in Times Square are taking pictures with their iPhones. The question isn't about specs. Of course the specs are getting better. The question is about how the decision Apple's made with this phone will trickle into all of the millions of iPhones they'll sell in the future. The biggest new feature of the iPhone 6S is 3D Touch, which lets you actually push into the screen to activate additional features. There's also a new 12 megapixel camera that can shoot 4K videos, and something Apple calls Live Photos, which are kind of like a combination of a photo, a GIF, and a video. Because the iPhone 6S and 6S Plus look just like the 6 and 6 Plus, I think it's fair to say that they're not the world's most beautiful phones. The weird antenna lines in the back and the slippery shape pretty much just demand that you put them in a case. But the body is made of a new, higher strength aluminum, and the screen has been upgraded with a stronger glass cover. So if you have an iPhone 6, you'll definitely notice that the 6S and 6S Plus are a little bit thicker and heavier than the previous models. It's not much, it's just a few millimeters and a few grams, but it's definitely noticeable. I actually prefer the slightly heavier 6S to the 6. It feels a little bit less like it's gonna fly out of my hands all the time. The extra size and weight comes from the 3D Touch components, which are a network of 96 sensors under the screen that measure the distance between the glass and the backlight. When you push down on the screen, that distance changes and the phone can respond. So on the home screen, pushing an icon gives you a list of quick actions you can take in certain apps. And when you're browsing in Safari, you can push lightly to get a preview of a link and push a little bit harder to pop it open into a window. It's kind of like a little right click for your phone. You don't really need it, but once you get used to it, it's incredibly useful. That dynamic, what Apple calls peak and pop, is really the key to 3D Touch. It's not just like a button. It's a way for the phone to sense an entire range of pressures all over the screen. When you press down an icon on the home screen, you see the background blur out in response to how hard you're pressing. It's not useful, but it's really cool. And it enhances the sense that iOS is all about layers of information, something Apple introduced to the iPhone when Johnny Ive dramatically redesigned iOS 7. 3D Touch feels like a big step along a path that's been taking shape ever since. But here's the thing. 3D Touch won't really be all that useful until all your third party apps start using it. Right now, it only really works in Apple's apps, so it's actually kind of easy to forget about it, especially since Apple's built-in iPhone apps like Mail and Calendar are kind of the weakest parts of the iPhone. And that means 3D Touch won't make a lot of sense for the next minute. There's not a lot of rules for how app developers should use it. We're going to need a whole language for all these new kinds of pokes and presses. It's going to take a while. The upside is that 3D Touch already feels much more natural than Force Touch on the Apple Watch, which kind of does wildly different things in different apps. And demos from apps like Instagram and others are pretty encouraging. And the potential for pressure-sensitive gaming is off the charts. 3D Touch might make games on the iPhone something much more exciting than just furiously swiping on the screen. The other big new feature of the iPhone 6S is the upgraded cameras. The most important change might actually be to the front camera. It's now 5 megapixels up from a tiny 1.2. That means it takes dramatically better photos and videos. Just the thing for selfies, Snapchats, and FaceTime. And the entire screen lights up as a flash, which means low light shots with the front camera are much improved as well. On the back, Apple's boosted the resolution of the rear camera to 12 megapixels up from 8 and added the ability to shoot 4K video. The iPhone has always taken the best and most natural photos of any phone, so this is a pretty mild update. The actual photos from the iPhone 6S aren't dramatically better than the photos from the iPhone 6. They're better, but not so much intensely better that you'll notice a difference if you're just sharing them on Facebook. You'll need to really blow them up to see the improvement. Both cameras can take Apple's new live photos, which are a little strange. When you press the shutter button, you'll see a little live indicator pop up letting you know that the phone is recording a few frames before and after your shot. Later, in your camera roll, you can 3D touch the photo to play back a short audio and video clip of what you've captured. It's neat, but you've got to remember to keep your camera pointed at your subject after you've shot a photo. I have a lot of live photos of me putting the camera down. You can share live photos with anyone using iOS 9, watchOS 2, or OS X El Copy Ton. Apple also says it'll put out an API to let live photos work in third-party apps and on the web, but I'm not really holding my breath for them to take off. If you want to record short videos, apps like Vine and Instagram already work great. They work everywhere, including Android phones. And live photos take up double the space of regular photos, so having every single photo you take include a short video seems like overkill. It's a cool feature that you should turn on when you want, but probably turn off by default. 4K video on the iPhone 6S looks great. Apple is very proud of the fact that the A9 processor can do all of the stabilization and image processing magic while shooting 4K, and then even edit two streams of 4K video in iMovie. That's legitimately impressive, but 4K video isn't actually on by default. You have to go into settings and turn it on. That's because it takes up a huge amount of space to record in 4K, and there's not a lot of places to watch that footage. You need a 4K TV or a really high-resolution monitor. Think of it as a pro feature. It's great to have, it'll be nice in the future, but you're not going to really use it day to day. That's kind of the entire vibe with the iPhone 6S. It's built for a much more powerful future. It has a ridiculously fast processor. It finally includes two gigs of RAM, so apps and web browsing are smoother than ever. The fingerprint sensor on the front is faster. And I got about the same battery life as an iPhone 6, around a full day with normal use. A little bit longer with iOS 9's low power mode, which turns down the brightness and underclocks the processor. That's fine, but I'm really hoping the next generation of phones lasts even longer. 3D touch is clearly a new kind of interface pattern, and the cameras are so good it's hard to even find ways to fully view what they can capture. It's a series of tiny, meaningful improvements to the already great iPhone 6. And if you're using an iPhone 5S or anything older, it's going to blow your mind. The iPhone 6S is the best iPhone ever, and probably the best phone ever. The future is great. But here's the thing. Until a couple weeks ago, the iPhone 6 was the best phone ever made, and it's still pretty damn good. In fact, I can't say that it's worth upgrading the 6S from the 6. It'll definitely be worth it when every app supports 3D touch, but by then, you'll be buying an iPhone 7.