This past week, I finally got fed up enough with iTunes Match to stop using it.
I've used it since it first came out. Back then, if you had a big library, album art pretty much only worked for half of your albums. Metadata, such as Play Count and Last Played, never synced between iTunes and your device. Maybe not so bad for most, but a major pain if you use Smart Playlists. Speaking of which, nested Smart Playlists are still not supported. Thankfully, the album art and the metadata sync typically work pretty well now.
Part of the problem is that Apple has not done a very good job about explaining what iTunes Match does. This compounded by the fact the some of the streaming behavior has changed multiple times. At some points it has streamed at lower bitrates when not of wifi. And originally it downloaded the track to your phone as it was played. Meaning once your iPhone got filled up with music you'd have to delete all of the music from your device and start over. Eventually, they changed this so that it only ever streams, with no option to download as you stream.
It also doesn't always match songs correctly. A particularly annoying example of this it that I have all of the Beatles Remastered Mono mixes imported into iTunes from the Mono Box Set and while the albums name still reflect that they are mono, they are most definitely the stereo mixes. Which is incredibly frustrating. Granted, the mono versions are not for sale in iTunes and I imagine that iTunes Match is probably just matching to the versions that are. Still, it should realize by the title and the file that they are not the same and upload my version.
The proverbial final straw for me, was that my wife recently signed up for iTunes match. We share the same Mac, but use different user accounts. When my wife signed up for iTunes Match under her user account with her iTunes account, mine stopped working. Apparently, you can only have one iTunes Match account linked to a device at a time. Furthermore, you can only change this once every 90 days. Which means that even though we both paid the $25, currently only my wife can use iTunes Match on our Mac. It still works on my iPhone, but it's kind of worthless if I can't use it on the Mac.