If you want the a la carte program package, make sure you buy a receiver that can get this. Not all of them can -- only the new receivers can. Most of the other radios allow you to pick and choose "Best of" stations from either, but they won't let you get the a la carte.
Re: Sirius or XM?
I could be wrong, but I thought I read somewhere that the two were merging...so it may not even matter.
If you want the a la carte program package, make sure you buy a receiver that can get this. Not all of them can -- only the new receivers can. Most of the other radios allow you to pick and choose "Best of" stations from either, but they won't let you get the a la carte.