I have XM.
Do not count on satalite radio to give you local weather or traffic, that was one of the conditions of Sirius and XM getting a licence in Canada - no local programming. Besides, why would a subscriber in Red Deer, Alberta care about traffic conditions in the GTA? You all get the same stations.
Listen to 680AM for free, the traffic comes on every 10 minutes, all day, every day
I find myself listening 95% of the time to three stations - 60's music, 70's music, and CNBC (its a audio feed of the US business network). The hockey is also good, they have 7 or eight games on at the same time, and you can see the score on the screen, so youcan do a quick check to see how the Senators are doing, even when you are in Leaf Nation.
XM and Sirius are in Merger talks in the US, I imagine the same thing will happen here, so it might not matter which service you choose in the end.