Right now I use musicchoice on Directv which I have connected to my home system digitally. Is is worth it to go to using XM? I know I would be able to use XM in the car, but I would primarely use it in the house. So I guess the real question is what would XM bring to the table? My music tastes are all over the board, but I guess I do listen to 80's music alot. Also one last question does the antenna actually have to be outside? My only outlet in this apt is the sliding glass doors which face west to northwest. Thanks!