The music app can get too deeply nested, but in general it is above all a consistent tabbed master-view experience in every app. The apis exposed to developers all lend to a very good, consistent experience for everything I’ve tried except YouTube TV, which doesn’t utilize the standard media transport API.
In general I like the idea that casting, while still as deeply integrated as Google Cast, is supplemental to the hardware remote. It’s not an afterthought, and neither is the remote. Both are good IMO.
Truly my only complaint is that the app switching dialogue uses reversed/“physical” swiping direction (like switching desktops with a trackpad). This makes no sense to me, as nothing else does this, including swiping between album covers in now playing. I get it, but it’s inconsistent with the whole rest of the UI.