The screwed-up music app is one of the major reasons I upgraded to 8.0 from 8.1. And yes, I mean every word of that. Windows Phone 8.0 is an upgrade from 8.1. Hubs, social integration, integrated music+videos hub, working photo hub, Bing vision, Local Scout,
and more.
The separate Now Playing screen was a major feature - swipe left/right to change tracks, tap the text underneath to access playlist, etc. Beautiful design. Now, you can swipe up/down, but that's not intuitive. Having Now Playing as a pivot is counter-intuitive. Just put it back the way you had it!