So give me plain old HTML any day. It renders fast, scrolling is predictable and smooth, and the URL is right there if you want to share.
This. I want the user to know they are on my site and be able to share the URL when they want to. Google News, admittedly the only implementation of AMP I've seen so far, fails in making visible that basic unit of the Internet -- the URL.
The worst UX sin though is when your finger moves ever slightly to the side, which is incredibly common when holding your phone. Most of the time Safari ignores that input as it didn't meet the threshold to go back/forward. AMP pages, however, seem to implement a canvas or something and wind up being really twitchy on left/right input. Not to actually go back/forward mind you, but to do something completely unexpected - reinterpreting left/right swipes to be navigating through entirely different articles. This is something one only discovers by accident, and something I'm not sure very many people would find utility in. It's another case where Google is trying to add their own entirely non-standard view of how UI should work rather than following the conventions of the platform they are on (ahem Material Design iOS apps).
And, just because they hadn't had enough of messing up typical reading UX, Google News AMP pages add a large fixed header so they could show you those many pages you can scroll through with little pagination dots. Sadly, this prevents Safari's own URL header from collapsing as you scroll down, meaning maybe 20% of your view is covered by interface instead of 5%. My assumption is that Google News decided that it was better for users to have the opportunity to view another article + their ads rather than providing a quality reading experience on the article the user actually wanted to read.
TL;DR: whatever AMP's tech offers is more than countered by the pointlessly awful implementation by Google News. If you're in an unfortunately enough situation to have to tap on an AMP page, the best possible outcome is to immediately go into Safari Reader View so your screen is 100% content and your every tiny input isn't likely to take you someplace you do not want to go.
But yes, I use the Samsung browser because of the performance and feature benefits, and my complaints may not be applicable to chrome.