Yes the majority of it is free, and yes you can sort the on demand content by the station it originally airs on. I can't say specifically how many shows are on Boomerang or comedy central since I dont tend to watch those, but most stations have from 10 to 100 titles on at any one time, and change often.
Remember On demand works over your high speed internet connection, so you must have Internet and either a network cable pulled to your reciever or a wireless adaptor.
Remember On demand works over your high speed internet connection, so you must have Internet and either a network cable pulled to your reciever or a wireless adaptor.