Yes it's worth it. I had my doubts at first but after using it for 30 days I paid for 3 years (to keep the monthly cost close to $10). If I sell the car before the end of 3 years XM will prorate a refund.

I've been using XM for 5 months now and rarely use AM or FM. The selection and sound quality is very good.

Note: I haven't even turned on my ONSTAR.

Steve
H3 white/ebony, auto, lux pkg, chrome pkg, chrome wheels, XM, sunroof, mudflaps, hitch, Hitchcam, RW chrome locking gas lid, etc.