Hi, depend of what project.
For example with old stepper motors nema 23 the skull girl take 9hours at 3500mm/min XY and 1200 Z and the skull 4 hours aprox (only 3D finishing roughing passes are 3 and 1:30 hours).
With new motors (nema 24 closed loop hybrid), i finished to wiring new control box with csmio, closed hybrid motors nema24 and spindle with 50-75% more power (from kress fme router to teknomotor 1.1Kw spindle) i want to try to make it at 3500-4000mm/min XY and 2000-2400Z (maybe the tapered ball nose bit doesn't have enough resistance, but i need to try it because if i double Z speed its a lot of time of machining 30-50% depending of accelerations i think).