I believe XM has had better radios over the years and my friends that have had both say that Sirius has better reception out here in the woody hills of western PA. XM has a lot more repeaters also, so it should pick up better in the urban and suburban areas..
I was looking at XM's talk channels too and some of my favorite shows are on at the correct times and are full shows. As some examples, Ed Schultz is on XM live from noon to three, a full three hour show. XM has Leo Laporte, "The Tech Guy". Sirius does not carry Leo, and Ed Schultz is not live from 3-5 pm with the last hour cut off. Stephanie Miller is only on for one hour at 8PM on Sirius.... There are many more too. I am a hardcore Stern fan and have had Sirius since 2005, but I think XM has better radio's and a better line up. Honestly ... XM with the best of Sirius is the best line up out there.... Plus you get MLB, NHL, NBA, NASCAR, and the NFL..
The XMp3 Needs WI-FI !!!