User kudzurebel on Apple’s discussion forum sums up the iTunes Match problems pretty well:
The big things that everyone is realizing aren’t being updated in the cloud libraries are “play counts”, “last played dates”, and artwork (I’m sure there are other things that aren’t updating properly). “Play counts” and “last played dates” seem to only sporadically get updated in the cloud under many circumstances. As far as I can tell, artwork changes never get pushed to the cloud. The only way to force the cloud to update artwork is to remove the track(s) from your library (and iCloud) and then re-add to iTunes and to iCloud with the new artwork in place. Otherwise the cloud eventually reverts your local library to whatever artwork you had when you first uploaded/matched the files.
The artwork problem may not seem like a big deal, but here’s an example where I’ve been struggling with it. I dislike greatest hits albums. If I rip a greatest hits album to iTunes I modify all the metadata to reflect each track’s original release information, including year, album name, track number, and artwork.
You have to dance with iTunes to get this working properly when Match is enabled. There are always sort problems. Usually marking all the ripped tracks as part of a compilation and then unmarking them as part of a compilation works, but sooner or later the artwork is going to change back to whatever the cover of the greatest hits album was.
I made a playlist called “See if this updates on iOS” to keep tabs on tracks I’ve played from iOS that may or may not get updated properly. Here’s an example.
All these tracks were played in the past week. One of them didn’t update its playcount at all. The other eventually updated within at least 7 days. Ratings are the only reliable thing about iTunes Match on iOS. Note how many tracks have a playcount of 1 but do not have a last played date. Not having last played date affects smart playlists built upon that information, like Recently Played.
One of the reasons the music nerds haven’t completely switched from iTunes to Spotify is because we have this level of detail in iTunes. But between the track limits, slow behavior on iOS, unreliable matching and syncing, iTunes Match harms the most valuable iTunes users: people who still love and buy music.