So I've had satellite radio for nearly 2 years now and have yet to have any hardware I don't hate. Ok, I've only had two different hardware solutions but still...
First I got a XM Snap and set that up with the AUX in to my sony stereo. It worked...kinda. The biggest problem was, every time I shut the car off, it turned off and reset to the preview channel. So, start the car up, turn the snap back on and hit the memory button to go back to a channel. Annoying.
Tired of that, I purchased the Sirius adapter for my sony head unit, thinking this would solve my problems. Uh, no. Once installed, it caused the sony head unit to shut off every time you start the car (this did not happen with the same stereo before hooking up the adapter). It's very strange, start the car up, the stereo flashes on and then immediately shuts off. On top of that, the satellite adapter only works about 75% of the time. At least once every week or two the stereo will forget that it has satellite radio at all, or will remember that it has it but will output no sound. This lasts a day or two (mostly, I just got over a week long spell of it not working) and then it starts to work again. Which, I know, sounds like a loose connection, but I've been over it a bunch of times and everything is tight and google indicates this is a common problem.
I really like my satellite radio, but I would like it to just work. Ideally I'd like an integrated solution, e.g. a stereo with satellite support. However after my sony experience I'm very reluctant to try this again. But if anyone knows a brand with a reliable adaptor (clarion, pioneer, etc) I would consider it. Alternately if something like the XM Onyx would be a reliable option (and at $40 cheaper than a new head unit and adapter) I'd definitely consider it...