Pandora's Blues stations kick ass. You couldn't ask for more and it is free. I listen to them a lot while I trade stocks during the day. There are no interruptions for an hour or two at a time then you have to move your mouse and it kicks in again. There isn't any talk, so it is easy to think while working.
Pandora has a lot of great things going on with it.
Don't cast it aside like junk just because you own SIRI.
Of course it doesn't have live broadcasts, but to a lot of people that just isn't important. There are people that just love listening to straight uninterrupted music.
My wife loves the SIRI Pure Jazz station (If that is what it is still called), because she loves the jocks on there that explain the backgrounds of the musicians and other trivia.
I have eleven sources for SIRI at my household. I listen to SIRI all of the time in my car.
Everybody is different.