I had Sirius installed with my new Ford for 6 months but didn't bother to renew. Howard Stern grew pretty old after a while, the comedy channels were all re-runs after listening for a couple of hours, and the 'punk' station played too much hip hop.
I'd much rather have XM and listen to the hockey talk all day like Hawgstoppah. Didn't help him out much in the pool, though!
Satellite radio was nice for longer road trips and I'd buy an XM radio now but I'm waiting to see what happens with the merger. Apparently the merger between XM and Sirius doesn't necessarily affect their Canadian subsidiaries.
Cheers,
PMD