You'll need the home docking kit for your Sirius radio, and then it's
very easy to connect to your home stereo system. If you don't have
the home docking kit, you'll need to get one if you want to connect
to your home stereo or powered speakers.

Yes, I thought the same thing--that paying for something you should
get free was ridiculous. But the content is much better, and fewer
commercials is a good thing. Really, you can't go wrong with either
system, but it seems to me that, because of how the Sirius satellites
orbit, you may (as I have) have more problems with antenna placement
using Sirius, especially if your city (like mine) doesn't have
ground repeater stations. XM's satellites are geosynchronous, so once
you get a signal, it stays there; Sirius has three satellits, and,
theoretically, when one goes out of range, another comes up, but I
have had some outages, though admittedly not many, with Sirius.