Just a few things that tells me iTunes Match is no where near ready for launch:
1. When you click a song from an album to download from the cloud, the rest of the songs from that album disappear from that list. The only way to correct this is to re-start iTunes, which takes longer than usual as now it has to connection to iCloud. Downloading (1) album from iTunes forced me to close and re-open iTunes about a dozen times. Picture doing that for 200 albums, or 500 albums... good times.
2. iTunes match is really spotty. My library is very thorough and accurate to the iTunes store, I purposefully make minor corrections to Title/Album/Artist to match the iTunes Store, so I can download album art more easily. Despite this, M. Ward's Post-War for example was not recognized in the cloud and once deleted could not be re-downloaded. His album is on the iTunes Store, and matches the copy I had exactly.
3. When re-downloaded they are not always restored as they were. An album will be downloaded partially, but singles featured on that album will be downloaded as "singles (separate albums) instead of as part of the full album. It's clear their database is only looking at the song title, instead of the album it came from, or anything else for that matter.