Two years of camera improvement are the biggest thing for me, low light and the 2x lens specifically are two big improvements from the 7 to the XS, letting me capture moments I wouldn’t have been able to otherwise.

In addition the OLED screen is night and day: you won’t want to go back if you switch, but I’d say that isn’t a reason to upgrade on its own unless you aren’t happy with the current one.

All that being said, like others here I too would prefer an iPhone SE form factor with similar specs. Maybe they will get back there but I imagine it will take a long time for the battery and screen and performance to all fit back into the smaller size.

If you find your camera to be adequate, then keep it. The screen is better both on XS and XR. I would still keep iPhone 7 for at least 1 more year before upgrading. The new XS and XR have the best camera on an iPhone but still doesn't match up to Pixel 2 or 3. I am certain in 1 or 2 generations apple will catchup.

There isn't one. That's the problem, phones are feature complete.

I bought the latest XS max because I wanted the bigger screen, faster phone, and nice oled.

>phones are feature complete

This is a much better explanation to slowing iPhone sales than people complaining about the missing head phone jack, the lack of TouchID, the notch or sizes. I don't think any of those design decisions have made any significant number of users pick Android phones when upgrading.

For most of us, there's simply no reason to upgrade from the iPhone 6 or 7, they're absolutely fine, and I'm not sure that the improvement in the camera quality is something that many will notice.

I'm not sure if this is the case in the US, but most carriers here don't have a 2 year upgrade plan, you don't get "free" phones anymore. You can get a payment plan, where you pay of your phone over two or three years, but they aren't getting you a new one, not even at a reduced price.

The problem also affects the software, I am getting the feeling that new OS Frameworks are being added, just because, like all the ML craziness.

Instead of focusing on what really matters in terms of developer productivity.

For me the full-front OLED screen, FaceID, wireless charging, better wide camera, additional tele/2x camera, portrait mode and FeliCa support all made the iPhone X a very enticing upgrade from my 6s.

If you don't care about any of those things then save your cash and don't upgrade.

None. Right now iPhone 7 is actually the most durable iPhone. It has no Glass Back panels, which replacement on iPhone 8 / X / Xs are insanely expensive. And its battery or well as other repair are the cheapest among the current line up as well.

I think the 4x4 MIMO antenna (for faster cellular internet) is the most enticing feature. Not enough for me to spend $1500 though.

I've found that increased LTE speeds on paper haven't really translated into real world speed increases for me -- my phone can do 1Gbps LTE on paper according to the manufacturer, but I've never actually seen higher than 50Mbps or so, even when within 100m or so of the base station with line of sight.

The Current iPhone XS implementation of 4x4 Antenna with Intel Modem doesn't work really well, I am hoping they will improved it in the 2019 model along with new Intel Modem.

Nitpick: the 4x4 MIMO antenna comes with the $999 iPhone as well, so you don't need to spend $1500 for it.

Seeing as Apple still sells the iPhone 7, I think they’re well aware that it’s still enough iPhone for some people.

The only sensible difference is portrait mode. X series are worse because Face ID has more friction than Touch ID.