Probably not base case but a quick test to replace my audio player (currently using Plyr) turned up the following gaps for me, at least with the out-of-the-box code.
1. No playback rates under 1
2. No volume rocker on mobile
3. Would appreciate having seek buttons on mobile too
4. No (easily apparent) way to add an accent color, stuck with boring monochrome
5. Docs lacked clear example/demo/playground so I wasn't sure what it would look like until implemented
All solid feedback, thanks! I'm making sure these get captured as issues. Otherwise we're closely tracking feature parity with Plyr (and other players) and our goal is to have full parity by GA, aiming for the middle of the year.