Never owned a 930S, but did own a 940S for years (similar, slightly newer, operated in mostly the same way) and bought an 850SAT in 1990 which I still own. I'd prefer the 850SAT for a few reasons, although "performance" is very similar. 850 is much lighter and easier to move around, but of course does require an external power supply. I think that's actually a "good" thing, as power supply failures in 930S units were a common problem and they're not cheap to repair. My 850SAT does have the internal ATU of course (it works well, makes a bit of noise in operation), and I added every filter available so all slots are filled -- they install really easily, you don't even need to remove the covers. I added the digital voice recorder option and the CTCSS option (to use 10m repeaters), which many wouldn't care about at all. It can be computer controlled. One feature the 850 has that the 930 did not was "CW-R" mode which provides strong rejection to adjacent frequency signals that may interfere in normal CW operation; just hit "CW-R" and that shifts to use the opposite sideband for reception on CW and can often take an S9+ interfering signal right down to zero at the press of one button. Depends on the frequency of the interference, but this can be very helpful at times. Most of the other controls are very similar. Given the choice of both "working" units, I'd pick the 850SAT but that's from experience with the 940S and not really the 930S.