I've been away from this thread for awhile. I have had no issues with the VP-70T on Buster.
Howsomever... my 54H cams don't really even come in until around 2700 RPM, and by that engine speed the VPC is fully extended and will lock the clutch up solid as soon as I engage it... with a not-so-nice little wheelie if I get TOO aggressive. I've done that 3 times, actually... it's a little scary to wheelie a SESG.
My "blasts" that Jeremey referred to are always made with the engine cranking at least 2500 RPM or more before I engage the clutch. If I don't crank the engine like that, with my setup there would BE no "blast"! 54Hs and my Drago's S/C/S-4 aren't exactly low-RPM torque hardware...
BTW - there is a NEW product coming to market soon that is designed specifically to reduce the clutch pull effort. Beta testing of this product has been going quite well - showing about 40% reduction in clutch pull. It will be considerably simpler and less $$$ than the AIM VPC, and will be a quick and easy install. I'm sorry, but I can't say anything any more specific than that right now - I have agreed to not divulge any details until the product hits the market. Hopefully it will be on the market in maybe a month or two. I've seen it, and it's pretty cool. It's not a racing device - but for you guys with heavy springs or issues with a left hand grip, it's a simple 10 minute bolt on.
When it comes out I'll post a link. If I didn't already have the VP-70T on Buster and my wife's Tri Glide, I would seriously be considering this new product.
You heard it HERE FIRST!