I've got one and am very satisfied with it.  The weight is a couple of pounds less and it is shorter than the McCauley governor.  It keeps the rpm within 10 or 20, much better than my old governor.  I bought mine from Whirlwind Propeller and they were good to deal with.  Only problem I had was that the calibration wasn't set as received and I had to fuss with it a bit to get the rpm I wanted.

Gary

ps:  I'm glad they didn't make me learn how to spell it before I bought!