I am interested but am more than a little concerned about the initial warm-up vibration for "several minutes". I am reminded of a carb balance I was doing several years ago and the idle sync was way off. I of course had the upper & lower cowls off and was amazed and concerned as I observed the engine vibrating severely. It just about threw off an air cleaner and I was visualizing the internal carburetor float and needle parts jumping around; fuel coming out the vents. I shut it down and fixed things right away, not wanting to let it run this way for even a few minutes. By the way it was smooth at rpms above about 3000. If the Balance Master allows anywhere near this kind of idle vibration every time you start it up for several minutes I would personally remove it and stick with conventional balancing and carb synchronizing. I would be very interested to hear from several who have installed the BM and have gotten out of the cabin and stood by the engine idling with the cowls off right after starting and report what they see for several minutes. If the engine/accessories, carbs, air filters, etc. look like a visual blur with fuel spurting from the vents I think we would all want to know this.