Actually I disagree, Doo clutching is better for belt grip for the bottom end and midrange (where most mountain riding is done), Poo clutching works better for top end stuff. The Doo clutches take a lot more set up but have lots more variables to play with, lots of guys hate on them because they simply can't figure them out. Polaris clutches were used by lots of Doo guys racing years back for simplicity, because you can change weights and profiles in about 3 mins without doing anything to the sled (on the Doo you have to take half the clutch apart to get at it) and the Poo clutch was lighter, so faster revs.Torque and clutching are the reason Pro's are competitive with less HP. Polaris clutching is just way better. Why else wouldn't the 160 hp totally dominate easily over the 145 hp sled. Assuming they lie equally, .
I think Poo has a winner chassis since the sled is balanced slightly better than the Doo. The sled was lighter so the performance advantage is comparable because the power to weight is the same even though the Pro has less of both, not because the clutching is that much better.
The belt drive helps lose that critical rotating mass, which helps with flow when riding as you are not fighting other weight or rotational forces on the chassis.I think the belt drive being more efficient than a chain helps as well putting more power and torque to the track. I've always believed this is the best setup. Just wish they would move the brake disc down as having no brakes if you break that belt makes me nervous.