I've made enough money in Doyle's money added or free roll tournaments to make playing their cash games with no rake back, worthwhile at least for me. Even if you do, what are you really making per hour for the 3 or 4 hours spent playing it it anyway! I would rather spend my time playing at a site where I have a much better chance of cashing in a money added tournament or higher paying free roll than some of the larger sites.
Full Tilt generally has over 2,000 players in every single free roll, giving most people little chance to ever get into the money. Through money added tournaments to free rolls with higher payouts than say, Full Tilts free rolls at $50.00.
Doyle's may not have rake back, as some of the larger sites do, but they make up for it in other ways. In fact, I enjoy playing at most of the rooms on the Prima/Microgaming network. I must agree! Ive played at just about every online poker room available to US players and have found Doyle's to be one of my favorite places to play.