Currently on a 6S. The screen broke and I was waiting until the release date to see which one I should get.
The iPhone compare page:
https://www.apple.com/iphone/compare/ makes all of the new phones seem really disappointing.
Yeah, they are faster. But I'm not really a power user, so that's not a big deal for me. Wireless charging is cool, but not a must have. The main difference seems to be the camera. But the difference doesn't seem big enough.
The 8 and X have 4k 60p (don't really care) and portrait lighting, which seems like a huge gimmick. They also add 1080p at 240 fps (the 7 only goes to 120 fps, you need to go down to 720p to get to 240 fps).
X adds a better front camera than both the X and 8 (which appear to have the same camera.
I do like the better camera and am probably going to get a new phone instead of replacing the screen (the volume buttons are also broken). But right now, I'm leaning towards the 7 Plus as opposed to the 8 Plus or waiting for X.