I have an iPhone 13 Mini and upgraded is iOS 26 and it seems fine to me.
I also have a 2018 iPad Pro and put iPadOS 26 on it and I haven't had any issues on it either except sometimes my keyboard is slow to connect. I'm not sure if it's the software or hardware though.
I haven't really found anything that blew my socks off, and the number of "strange bugs" (not even talking about the UI complaints, just things like "touch stops working suddenly" and other weird things) is too damn high.
