Even though I had only an EDGE connection, the experience was fine. The app did take a while to start up and play the first song, but then I just listened to music. Some of which I already own, some that I think was new to me. But all worth listening to, and all free. And I didn’t hear any “buffering” style pauses — just continuous music. (There were apparently ads, but only on screen.)
Pandora Radio is not built in like the iPod application, so you can’t do anything else while it’s running, but I didn’t need to.
It’s worth getting this, and spending a little time customizing it so it can recommend music (I had originally done this a Macintosh using their online service — your account is available from any device).