While I'm very impressed that I only have 500 pieces of content form the iTunes Store, yet iTunes Match successfully matched 15000 of my 20307 items in my library, I have a problem with the remaining unmatched items. They won't upload successfully, and, worse, the upload hangs and neither times out nor alerts the user that it's not working.
I turned on iTunes Match a few days ago and the "Step 3: Upload artwork and remaining songs" phase has not completed once. The pattern is that it hangs after 800 items or so. The last hang was "904 of 4414 items". The previous hang was "879 of 4445 items".
My definition of a hang is that the number doesn't change for an hour or more after changing frequently beforehand.
I've plenty of bandwidth available, the song files play just fine, but the upload simply stops.
Ok, I now see that this is very common and there's not much I can do to fix it. I will certainly NOT be converting my library to some other format so it can be seen. This is Apple's problem, not the poor end-user.