Lobby - I think an ATCO should have a good idea of the general handling & perf characteristics. Our mantra is "safe, orderly & expeditious" and while you can have the first, you can't get the second or third without the knowledge. You don't need to know the V(at) of a half-laden 744 but you should know that helo's are safer in a small orbit with some forward speed than in a hover.
ap