I have Sirrius in one of my cars. Love it. But I hate the cost.
The fact that you have a 100+ channels is fantastic, but as with TV I find that I use only a small % of what is available. The fact that the channels never fade out as you drive into the rural areas is a huge bonus. I can drive from Chicago to Indianapolis and back and never have a signal fade. Using traditional FM radio I'd have to search the dial several times during that trip and using AM radio it would take a couple of searches to keep some station or another tuned in.
I don't listen to country music but I know they have a couple dedicated channels just for that. Along with dozens of other music channels. They have a bunch of news channels, lots of talk channels (left, right, ladies topics, sex, you name it). A bunch of comedy channels from 'family friendly' to seriously raunchy.