Not true, Sirius only has 60 out of 100 commercial-free channels, whereas XM only offers 35 commercial-free.
There's also the issue of an antenna. Automobile sattelite radio requires the installation of an additonal antenna, which was definitely not for me.
For home use, you may not be able to pick up a signal with the antenna installed indoors. Sirius recommends possible outdoor installation, but depending on how your home is constructed, may not be possible with the home-use antenna. The only way I was able to get a signal at home was to set the entire damned thing up outside, way the hell away from the house and all trees (yeah, they can affect the signal, too).
I wound up taking my Sirius setup back for a refund (I paid $195 plus a $50 rebate for the receiver, car docking kit, and home use kit). For me, sattelite radio has a ways to go before I'm willing to commit. You may feel differently.