They do not work as well on iOS. Two examples of this are "scroll to top" by tapping the title bar is completely broken under AMP. The other is that Safari Reader is mostly broken under AMP. That said, the experience with super fast, virtually instant loads, is great, and I think these are definitely kinks that can be worked out.
I'm just confused why they made it through to consumer release without someone else questioning them. These are major features of the most popular browser on [one of the two] most popular mobile OS that Google is choosing to break.
Edit: Added "[one of the two]"