I have to join the chorus of regrets here. I have an iPhone 7+, 256GB, AT&T. Since updating to 11 (and its subsequent .x releases):
- My battery life has diminished by more than 30%. Got between 7.5 and 8 hours of active use from a full charge on 10; get around 5 hours on 11.
- The notifications panel just disappears for no apparent reason. If I activate when the screen is locked, all I see is my wallpaper. I have to restart the phone to get it to display again.
- If I'm talking on the phone while it's locked, the phone control panel screen will randomly activate. I've been using AirPods and keeping the phone in my pocket. I'll suddenly hear touch tones, and it's because the control panel has activated, and then the key pad opens and random brushing against my leg presses the numbers.
- Cellular service, call quality, and data speed has degraded. I rarely get more than 2 bars indoors or out, and streaming video over cellular is choppy, even at low quality.
I've always upgraded to X.0 releases within a week of the general release, but Apple has done its user base a disservice with iOS 11. It still feels like a beta, and each subsequent release is met with disappointment as it fails to correct any of these issues. I'll probably do a factory reset of the phone over the weekend to see if it clears up any of these problems; as somebody who works in software, I would be mortified if I had to tell a customer that was the only course of action to correct bugs spawned by an update.