I've just installed the Dr Pulley variator model for GY6 150 (on a 2009 People 150). Perfect install. However, there are no holes on the outer sheave for a pin wrench to properly torque the nut. You'll need a strap wrench or flywheel holder that could engage the cooling fins on the sheave to hold it still, unless you're willing to use an impact air wrench to tighten it and hope for the best. I had already made an adjustable pin wrench for the stock variator, so I stuck the Kymco stock outer sheave on till I can get the proper strap wrench. I used 13gm Dr Pulley sliders (not rollers) Some increase in low and midrange response, possible decrease in top speed. I've ordered 15gm sliders to try as I'm interested in getting best top speed that I can.
Waiting on a Malossi Kevlar belt, so using the stocker for now.