The rear slide serrations on the back of the compact .40 are pretty deep and sharp; I've not had a problem being able to get a good grip (and my index finger usually lies across the top of the slide just in front of the rear sight, so there's some extra push there too).
I can say I've tried with really wet hands, but as far as the serrations go, the ones on the compact .40 are more severe than the full size 9mm 75s, though as you note the .40 springs are a bit stiffer.