Yeah, I thought that at first as well. BUT, you have to give it time to sync. Going in and seeing no art and then giving up on the program doesn't give it a chance to sync the album art needed.
I have spent about 48 or more hours testing this out. After the first 24 hours or so, all my album art was showing up for over 500 albums. Even album art that had no art online but had art in the local folder. I know it had no art online because there are a few albums I made myself, using my own recordings, and I also created the album art. I know for sure it got the local album art along with online album art.
In my opinion, it does the album art WAYYY better than XBM, once you give it time to sync.
If others aren't getting album art after giving it time to properly sync, then I don't know what to say. It's working great for me.
I picked up a spare Lumia 635 after I bricked my current one last week. With Pankaj's help, I was able to recover my bricked 635. Now I have one that is not my daily driver to test out TP with properly. Having a great time with it, and now I get to use the better music player. That's the main reason I decided to put 10 back on the secondary 635 that doesn't have a SIM... just so I can use the Music.