I have a kit on one of my pros with a 3" track. I have another pro with no kit and 2.5" track. You can defiantly tell the difference. Not sure how much is track and how much is drop/roll kit.
I picked up a 3 powerclaw and have to make some decisions on which way to go. My concerns are with 8 tooth drivers hanging to low and bending shaft and also with handling of sled. Will a suspension relocate be in order with this mod? Normally have to give something in order to gain. I have turbo power so was thinking of toms belt drive anyway. I have spun one Polaris belt with 2000 miles on it. The 3 is going to hook way harder than 2.4 pol.
The avid kit lowers and moves the suspension back. I didn't ride it a lot before I did it, but it have rode several other pros, I think it improved the handling. I had a 15 pro with a 3 inch and 7 tooth drivers. The drop and roll definitely worked better. It's a little more money, but avid also does a drop and roll belt drive.