depends the situation, with a ati hd 4850 radeon is better solution if you don t need opengl 3.3 right now, with kernel 3.11 the things are good
Well, the old rule is still as valid as ever: use radeon if it's good enough for your use case, use catalyst if not. Just that nowadays radeon is sufficient for more people than before (while catalyst is starting to become insufficient due to its own problems).
Actually Iím not missing anything with the free drivers. That might be connected to just not using the unfree drivers, though. Iím not interested in unfree stuff, when there are free solutions which support all my workflows.