I am!
I have three ESRs and a GoQuad kart:
ESR750H PPV with Torkinator: revived the 4 LiPo packs a couple of months ago and been truly enjoying it since
ESR750 #1 (good motor, mostly complete): just ordered replacement SLAs (I know SLAs suck, but I found a good deal on a set of new deep-cycle...