the main one i'm thinking of is Jimmy Bruno. When he gets really burnin', it's almost all forearm.

Joe Pass does it a bit too. Both those guys float their hand above the strings.

I'm not sure any rock p_layer_s do it, but a great picker who you should check out is Steve Morse. He has his own technique of holding the pick with 3 fingers, and anchoring with his pinky. I do that a bit too - anchor my pinky and then close the rest of the fingers. It's a happy medium between floating and anchoring.

Petrucci is another one, who floats when he gets super fast, and it's a combo of forearm and wrist.

To each his own, I guess. I would say find what works best for you and is comfortable at any speed and stick with it.