As @CyanoticWasp said, results can be spectacular. When my lady and I found her “spot”, her climax was so intense that I thought she was having some kind of seizure. She’s also a “squirter”. We found it about 3” in, somewhat deeper than the literature says and deeper than she could comfortably reach with her own fingers. It didn’t have a “rough” feeling, just a bit less soft She preferred two fingers stroking on either side, initially very gently and increasing in firmness (but not speed). In combination with clitoral stimulation (lips or tongue), the orgasm was so intense that she would be “off in space” somewhere for 5–10 minutes afterwards and would take about 30 minutes to fully recover.
Her girlfriends G-spot is located about half that distance in (about 1½’). She responds best to direct stimulation with one finger, in a circular rubbing motion, quite firmly and without any other stimulation. She prefers either clitoral or G-spot but not both. Her climax response longer but less intense.
This is only two points on the data curve, but it does indicate that there are differences in location, preferred stimulation and levels of response. It’s also interesting to note that my lady in orgasm would spread her legs as widely as she could while her girlfriend would clamp down like a nutcracker (strong legs, too).