From Joanna Stern’s iPhone 6s review for the WSJ:

Let’s get this out of the way first. The No. 1 thing people want in a smartphone is better battery life. And the iPhone 6s doesn’t deliver that.

And:

Still, there is no battery improvement over last year’s iPhone 6 models. In our grueling test; which loops a series of websites with brightness set at around 65%, I found the 6s and 6s Plus get no more—but also no less—battery life than their predecessors. (iOS 9 itself adds an hour of savings to the iPhone 6, and has Low Power Mode.) Strangely, although Apple says that the 6s Plus gets hours more battery life than the 6s, repeated testing on multiple devices reveals a slimmer difference. In a Web surfing test, the 6s on average lasted for 8 hours, while the 6s Plus went 20 minutes longer. In a video playback test, the difference was an hour.

This is a common theme in reviews I’ve read this morning. Given that Apple had to ship a smaller battery to make room for new components, the fact that the 6s is still getting the same performance on a more powerful hardware suggests that iOS 9’s optimization technologies are working.

The iPhone 6s review embargo lifted this morning. As usual, the first review of a new iPhone I read is Jim Dalrymple’s:

Peek and Pop work all over the place on iPhone. In Apple Music, you can use it to view albums and playlists; you can view Messages and texts; You can set calendar events, view flight info, view images and videos and all kinds of other things.

3D Touch is one of the handiest features that I’ve seen from Apple in a long time. It’s not just that it’s cool, it actually saves me time. It’s a new way to navigate the iPhone that’s quick, easy, and efficient.

From Jason Snell’s story for Macworld on trying 3D Touch at Apple’s September 9 event:

Every time I intended to use 3D Touch to “push” an icon on the iPhone home screen, the feature activated and a contextual menu popped into view, accompanied by a tiny vibration to indicate that I had succeeded with my gesture. The extension of that gesture–sliding my finger or thumb down to the right menu item and then letting go–felt natural after a single try.

When I used the iPhone without attempting to enable 3D Touch, it didn’t enable. When I tried, it worked. In Messages, I was able to push on a message preview and receive a “peek” at the full message, with accompanying vibration. When I wanted to commit to opening that message, I pushed a little harder and was greeted with another vibration as the full message “popped” in.

More than haptic feedback and shortcuts, it sounds like 3D Touch will fundamentally alter the navigation experience of iOS. Several iOS 9 features (new app switcher, back button, Universal Links) make more sense in the context of 3D Touch, too.

I missed this story by Josh Tyrangiel for Bloomberg Business on how Apple’s design team approached the idea of bringing pressure sensitivity to the iPhone’s screen. I liked this bit with Craig Federighi:

But in lieu of the usual polite deflection, Federighi picked up an iPhone 6S and explained one of 3D Touch’s simpler challenges: “It starts with the idea that, on a device this thin, you want to detect force. I mean, you think you want to detect force, but really what you’re trying to do is sense intent. You’re trying to read minds. And yet you have a user who might be using his thumb, his finger, might be emotional at the moment, might be walking, might be laying on the couch. These things don’t affect intent, but they do affect what a sensor [inside the phone] sees. So there are a huge number of technical hurdles. We have to do sensor fusion with accelerometers to cancel out gravity—but when you turn [the device] a different way, we have to subtract out gravity. … Your thumb can read differently to the touch sensor than your finger would. That difference is important to understanding how to interpret the force. And so we’re fusing both what the force sensor is giving us with what the touch sensor is giving us about the nature of your interaction. So down at even just the lowest level of hardware and algorithms—I mean, this is just one basic thing. And if you don’t get it right, none of it works.”