Funny you should ask. I bought iTunes Match on the day it launched. I felt the service was only okay. I was more happy that my 128kbps or less files where now iTunes Plus files direct from Apple. What I didn't like was the syncing. I felt it really could have used a "Sync to Phone" or "Stream" to phone option, so I can decided depending where I was. Instead, it downloaded everything to my device.
I didn't go past the first year, but I opted into it again in January of this year and nothing as changed. In fact, last night, I deleted everything in my iTunes Match (now shows 0 songs in the cloud) and I am simply using plain old iTunes now. The reason is because:
1) Apple hasn't bothered to improve the service since launch day.
2) Like all other Apple software, it barely works or won't see an update in years.
3) The Match algorithm is flaky. I'll have a complete album that will Match all songs but one that gets uploaded, even though the song is clearly in the iTunes Store. Messes with my OCD and I got tired of jumping through hoops trying to get it to Match.
4) The service takes FOREVER. Out of the 24k songs I have in iTunes, every time I had a new album, the Match takes over an hour to match just that one. I guess Apple is not looking at the delta changes, but this is absurd. Sometimes the service won't even pick up the new album and will say "waiting", so I can to run the service again, causing more time delay.
5) The never solved the issue with Explicit lyrics. I want my cuss words the way the artist intended.
I'm sending my complaints to Apple and hope they give me a pro-rated refund. iTunes Match is completely turned off on my system due to lack of support and usefulness. I'm looking into Amazon Music for my cloud music needs.