Works fine for me. Over 20,000 songs on iPhone, iPad, computer in my study, computer at work. It even matched songs that I recorded myself from LPs.
I have less than 1000 songs in iTunes. It's been nearly 2 weeks, and Match hasn't finished syncing them. It keeps trying to re-sync songs that are already in the cloud. When does manage to sync a single song, it relaunches the entire process of searching my library and trying to match the results with Apple's servers. And I always end up with the infamous "unknown error 4002." I've been through all the supposed resolutions to that problem, even having a long conversation with AppleCare. (The guy had me convert a bunch of songs and delete some others. That still didn't solve the problem.) Match has been gradually syncing my library, but only about a dozen songs per day before it halts. If it were a beta, like Siri, I'd cut it some slack. But I'm paying for a service that I expected to be a bit more seamless.