Found this
Flight test report for the 767-400ER which said for 1/2 control wheel deflection a roll rate of 15 deg/dec was observed, how that compares to a 757 or a non 400ER I have no idea.
We entered an arbitrary working area into the Honeywell Pegasus FMC and set up for some flight maneuvers northwest of Moses Lake. The first was a check of roll rate in bank-to-bank rolls from 30 degrees to 30 degrees at ½ wheel deflection. Flying the clean airplane at 350 knots, bank-to-bank took 4 seconds, for a roll rate of 15 degrees per second. Here is where a sharp control input initiated an aeroelastic response from the airframe. A later check of this same maneuver with flaps 30 at Vref=136 gave a bank-to-bank time of 6 seconds, or a roll rate of 10 degrees per second. This excellent response at slow speed in the landing configuration is another indication of the exceptional handling qualities of this airplane.