My old PDP11/73 (now in a museum) had two RX02, never had an RX01. Surprisingly fast! It also had two RL02s and a couple of RD54s in.

Building an RT11 system disk onto an RL02 off another RL02 made the downstairs neighbours complain quite a lot, even though the floor slab in my flat was about 40cm thick concrete. They didn't muck about with these 1960s tower blocks but it was no match for a pair of pint glass sized head actuators and a pair of washing machine motors.