I cruise (although I prefer to do it quickly) so I can’t answer for the racing folk, but in a real F5 I would be reefed.
But to come to the question – does reefing deprive you of control? I don’t think a single reef should, the boat sails rather well reefed in a good wind. If you are reefed but pinching and spilling wind to survive, then something may well be wrong with the setup. Keith has mentioned genoa size. The other possibility is that the reefed main has a poor shape – if you have a ‘baggy’ reefed main you may have the worst of both worlds.