I've somehow managed to avoid most of those issues on a iPhone 7 and iPad Mini 4. However, I am having issues with audio playback and with Bluetooth, as well as WiFi "forgetting" passwords (I get "password incorrect" prompt, re-enter password, it is rejected, Settings -> General -> Reset -> Network Reset, reboot, and it's back to normal for a few days).
With audio, it will occasionally hiccup or skip. With video (especially Netflix), it will skip or become choppy for a few seconds. With Bluetooth, my car stereo will switch from another source to Bluetooth Input whenever I receive a text, then it will not revert to the original source input (CD, terrestrial radio, etc). All of this only started happening after the iOS 11 update, and all of the above issues persist across both devices, so it's not a hardware thing.
With audio, it will occasionally hiccup or skip. With video (especially Netflix), it will skip or become choppy for a few seconds. With Bluetooth, my car stereo will switch from another source to Bluetooth Input whenever I receive a text, then it will not revert to the original source input (CD, terrestrial radio, etc). All of this only started happening after the iOS 11 update, and all of the above issues persist across both devices, so it's not a hardware thing.