I've been with Sirius since 2004 and really like it. That was the first season they carried Bama football and it was funny how sometimes kickoff time would approach and they hadn't switched from regular programming to the game. I would literally call Sirius, tell them about it, and within a minute the game would be on. (They've gotten better about that since.)
The pre- and post-game coverage is a little spotty. Sometimes you get an hour of CTSN both before and after the game, sometimes less, and sometimes none at all. It depends on their schedule of other games, if games run late, etc.
If you do get Sirius (or XM, for that matter) plug-and-play unit, make sure to get one that fits into a portable boombox, and get the boombox if you tailgate regularly. I have one and really enjoy listening to the other games or scoreboard shows as we tailgate (especially if Barn or UT is getting beat!).