I've been wearing mine for nearly a week and my balls seem larger, the loads are definitely larger, and the overall effect is such that I feel heavier and firmer in a flaccid state. Since I do a lot of edging : ) I've also noticed much more strength in the unit when erect and intensity of orgasm, which is always high when edging, is going through the roof.
I'm using it as well to flex the base by kegelling and the result is intense. My goal right now is girth and this device seems like it will really produce results.
Some users report no feeling of warmth or electric charge, and I have a difficult time explaining it, but I feel something there and it's great. It sort of comes and goes.