This thing is the shiznit. Got mine yesterday and re-balanced my oilhead when I got home just for the hell of it since the ports are easy to get at. I'd gotten pretty close with the Twinmax but it was way easier with the Harmonizer, especially doing the 3krpm throttle cable balance, which was a pain with the Twinmax thanks to the bouncy needle but was a piece of cake with the Harmonizer.
Today I used it to balance the throttle bodies on my '04 Wee. I dunno what had been done before (I've owned it for 5 weeks) but they were 50mbar off. Turn screw to find zero..... EPIC WIN. These bikes are smooth to begin with, but now if I were deaf I'd have to look at the tach to know if it was actually running below about 5krpm.
This device is awesome. Buy one now while you can still get something for your Twinmax second hand
(and no, I have nothing to do with the manufacturer/seller besides living in the same county and having bought one from him)