Gave up on Amazon Cloud Player and Google Music already
I put about 10,000 tracks on both Amazon and Google about a year ago (I have a lot of CDs and a robotic ripper...), but have since given up on both of them.
They work OK when they do, but too often they ignore the perfectly good metadata and cover art and misidentify what I've uploaded as something entirely different. Believe me, you don't want to be listening to a playlist at the office and having the cover art for "101 Strings Plays Your Favorite Porn Themes" pop up on the screen. And I have no idea what either service would do with digitized copies of vinyl or tapes.
As for AutoRip, that's very nice when I buy something on Amazon. In the US. From Amazon. It doesn't appear to work for Amazon Marketplace purchases. Forget about amazon.somewhere-else. But when it works, it's nice to be able to listen immediately.
It's was easier for me to set up a Subsonic server, "uploads" take close to zero time, I can rip to FLAC and it transcodes to MP3 on the fly, I can only blame myself for bad metadata, and I get to choose what's available to listen to and not Amazon, Google, Apple, or some other company that basically doesn't have my musical interests at heart.