Well, then I guess I am special. I've never had problems with iOS releases.
Both iOS 7 and iOS 8 were debacles for me personally; they both screwed up the way my running app (Runmeter) interacts with the GPS. 7 straight up broke it, and 8 threw the distance tracking waaaaaaaaaaay off. So I'd run one mile, and it only only credit me for .75 miles. Anyway, point being, iOS releases tend to be solid overall, but if your favorite apps don't work with it, or even cause issues with the OS itself...
I do think it's funny how some people dismiss the indexing/cleanup that happens after an upgrade after every single iOS upgrade ever. Yeah, your phone is going to run hot for a while, burn a ton of battery, and be pokey. EVERY major upgrade, and some point releases, do this. I'd expect new iPhone users to ask questions, but come on. It gets old.