I think it's pretty nifty. I have Greatful Dead, The Doors, and The Rolling Stones stations (among others) on my Pandora.
One thing I don't like is that they don't always play songs exclusive to the station of the band. For example, on the 'Dead station, they'll play a 'Dead song, and then maybe an Arlo Guthrie and then Bob Dylan, and then another 'Dead song. So, they'll play music similar to the genre of the station, but not EVERY song is from that specific artist. I wish it COULD be like that (exclusive music from chosen artist). BUT, you DO have the option to FF thru five songs per hour per station on the non-pay version.
I believe the paying version you can FF thru as much as you want.
The thumbs up/down feature is great, too. I THINK they use it as a sort of gauge on what to play on the stations.
The ads don't bother me much. I am getting it for FREE! I'll go along w/ a little advertising to get such a cool service. After all, if I want to pay for it, the ads disappear!