After a lot of initial teething problems with Match (which completely screwed up my music on my iPhone!) I now have an annoying problem where album art doesn't seem to have been transferred to my iPhone.
Whenever I play a song on my phone, it has to download the cover art, then I have to back out to the tracklist and then hit the "Now Playing" button for the art to show. It seems to save the art for that track from that point onwwards, but it doesn't fix it for all tracks in the album.
A quick google suggests it might be down to oversized album art and a resize to 50x50 will fix it, but as I have an iPad that shows album art in full screen, a 50x50 image would look terrible blown up to fit the screen.
It's a real pain!
Doesn't work on my iPhone either, I'm getting problems where it thinks the song is download, but doesn't play it, it just skips over it.
For now I've disabled match on my iPhone and just sticking with it on my mac, where it actually works well.