MacBook Air (13-inch, Early 2015)
Since Sierra - Scrolling an open window to view folders sticks, sidebar disappears when trying to scroll, can't scroll down unless I close and reopen the folder. Safari hangs, clicking on buttons does not work sometimes, pages don't display properly (Multiple sites) When attaching an external monitor, I lose most of my choices of resolution. 1080 or 2160, nothing in between (Known issue BTW). Tried several monitors. Quicktime freezes or hangs, freezes up the whole computer sometimes, SD card does not appear when loaded, networking issues... I can keep going. None of this happened in El Capitan.
iPhone 6
iOS 10 - Random freezes, software update sometimes works sometimes does not. Hotspot using bluetooth super buggy. Sometimes will not connect at all. A computer and phone restart sometimes helps. Carplay almost unusable since update. Touch ID more finicky than it used to be. Sometimes I cannot slide the bar to answer the phone. Does not work at all... Again, I can keep going.
But you are right, whose anecdote is worth more?
Unless you imagine that these serious issues afflict everyone with devices that sold in their 10s (100s?) of million for the iPhone 6 and millions (hundreds of thousands?) for the 2015 Air, which they clearly didn't since Apple would be out of business, I don't know what to tell you. Find someone competent to help you.