I can't decide between XM or Sirius Satellite Radio, help please?

I've been looking at both of them. I'm leaning toward XM because it looks like it has more music channels. I'm really not sure which one to go for since they are the same price? I drive a Scion tC and also would like to know the best radio for my car specifically. Thanks in advance. Also any experiences with either of them would be greatly appreciated.