The things mentioned by other people - message notification lag, stupid slidy cards for brightness and volume, lockscreen press home button to jump through hoop. Also
- Photos. Wtf is the distinction between 'photos' and 'albums'. Why does Photos pretend to be a chronological hierarchy of Year -> Month -> Day but then drop to Tumblr style 'related' links, while Memories contain your grouped photos in any order, but so does Albums. Albums also try to dynamically group things by 'location' and 'selfies' and 'video' and 'camera roll'. Oh, they're all showing the same thing - the last thing I recorded? Useful. It's a complete mess and super frustrating to use.
- The changes to take and send photos in iMessage. Used to be that taking a photo meant pressing and holding the photo button, sliding up to take a video. Now it's more steps, and the camera shutter button is awkwardly at the bottom of the screen, then there's another slider to the left to reveal another camera button, to switch to the camera app, to take a video. More steps for everything, which also displaces 'insert a previously taken photo'. Who benefits?
- Video editing (trim) was glitchy in iOS9 and still is in iOS 10. Seriously, take photo, play with trim, randomly the video stops changing with the slider position, then the screen goes black, have to task-end the Photos app and try again. Video playback in Safari, also glitchy - pause somewhere, or skip forwards, get it playing from the start at 10x framerate (or more) with no audio, to 'catch up' to the new seek location. Seeking is still fiddly and often doesn't work well.
- Still need to care about WiFi vs. Cellular because "we changed our App icon to a Christmas one" still means tens or hundreds of download.
- Photos. Wtf is the distinction between 'photos' and 'albums'. Why does Photos pretend to be a chronological hierarchy of Year -> Month -> Day but then drop to Tumblr style 'related' links, while Memories contain your grouped photos in any order, but so does Albums. Albums also try to dynamically group things by 'location' and 'selfies' and 'video' and 'camera roll'. Oh, they're all showing the same thing - the last thing I recorded? Useful. It's a complete mess and super frustrating to use.
- The changes to take and send photos in iMessage. Used to be that taking a photo meant pressing and holding the photo button, sliding up to take a video. Now it's more steps, and the camera shutter button is awkwardly at the bottom of the screen, then there's another slider to the left to reveal another camera button, to switch to the camera app, to take a video. More steps for everything, which also displaces 'insert a previously taken photo'. Who benefits?
- Video editing (trim) was glitchy in iOS9 and still is in iOS 10. Seriously, take photo, play with trim, randomly the video stops changing with the slider position, then the screen goes black, have to task-end the Photos app and try again. Video playback in Safari, also glitchy - pause somewhere, or skip forwards, get it playing from the start at 10x framerate (or more) with no audio, to 'catch up' to the new seek location. Seeking is still fiddly and often doesn't work well.
- Still need to care about WiFi vs. Cellular because "we changed our App icon to a Christmas one" still means tens or hundreds of download.