"""""""What happens if you turn off object snaps and then do the simultaneous movement while """"""""""

That doesnt change anything. Empty viewport is fine. Add a sphere and issue is there. No need to be in command or picking type mode. Actually, going into a command, like drawing a curve, creates smooth movement!!! So I place a sphere and get buggard, then start a spline command, and get smooth (Although a little more laggy, which is expected and not some unusual amount)....