I have to second the OP here. I have installed almost every beta (except for iOS11 which I skipped) since iOS8, most of which were by far more usable than the freshly released final version of iOS11, which is super buggy for every iPhone user in my vicinity (being in an Apple-only work environment, there's quite a few of them). It does impact our workflow quite severely, when the native apps we rely upon crash every few seconds before we can complete a task. The crashes and general slugginess have been confirmed to me by a couple Apple Store employees who are experiencing them on their own devices, and do collect clients' feedback all day long. So it is definitely not an isolated case.