i m gonna agree w someone above. i like sirius better, a little bit more expensive but the selection of music is better. sirius $12.95 a month, while xm 9.99 a month. however, xm only has 30 commercial free channels, while sirius has 60.
havin that been told, xm is too repetitive imo, i work at cc, so i know, we listen to xm or sirius all day long. u become tired of the songs in xm just cuz they play the same in a loop in jsut one channel taht is.
while for sirius, there's more variety, n every song is 'fresh' cuz u dont hear it like 5 times in 6 hours or so.
i'll go w sirius myself, i believe only pana & sony (correct me here)
i know alpine, pioneer do xm.