I have a subscription. For jazz and classical music, it’s great; for rock and country, it’s okay. “Hot” artists tend to be unavailable. You want the latest Britney or Eminem, you’re out of luck, or even Beatles and Stones. But their selection of second-tier artists is vast. You can rarely find your first choice of anything, but they have plenty of other stuff in stock you’ll probably settle for.
Download time: I have a dial-up account (56k), so it takes a while, maybe two hours for a typical album. I usually key up two or three albums’ worth before I go to work, and it’s all downloaded by the time I get home.
They get new stuff daily, but it usually isn’t anybody you’ve heard of.
For classical, they don’t have opera available, or top-of-the line name performers (No Pavarotti, Yo Yo-Ma, Sarah Chang or Eroica Trio). But they have all the major pieces of music by all the improtant composers, usually by someone you’ve never heard of. I’d never heard of the English Guitar Quartet or Liona Boyd before, but I’m certainly a fan now. They have all of Beethoven’s Symphonies by Furtwangler. They have vast troves of stuff, divided by style (Baroque, chamber, medieval, romantic, what have you).
Their jazz selection is a bit stronger. Not a lot of hot contemporary performers, but that’s a good thing. They have extensive selections of Miles Davis, Ella Fitzgerald, Louis Armstrong, Bird, 'Trane, Django… The jazz selection alone is well worth the subscription fee.
Country? Pretty weak. Lots of cool old stuff, apparently including everything ever recorded for the radio show Louisiana Hayride. But if you’re looking for Dixie Chicks, Dwight Yoakam, or Mary Chapin-Carpenter, this really isn’t the service for you.
I’m not real knowledgeable about blues, electronica, Caribbean or World Music, but they have a lot available.
Classic rock-- a few gems here and there. Lots of Kinks albums currently, a lot of Ringo Starr All Star Band. But not quite enough to warrant a subscription for. This is truer of their contemporary pop/rock selection as well. They had most of the Elvis Costello catalogue available last year, but last time I checked, it was gone.
Look through their archives and see if they have enough of what you want. I think they’re okay, but my subscription ends this month and I won’t be re-upping. I will be downloading like a mofo between now and then, though…