What I have noticed is the Dayco doesn't engage as smooth as the OEM belt, it is a bit different. And I only noticed this on a stock sled.
With my M1000T I can't tell any difference. Other than my pocket book has a bit more money in it to buy race fuel. The stock belt prices are way out of line, the $120 or so for the dayco, with a one year guarantee and a $15 dollar replacement it pretty darn hard to beat.
One other thing, make sure you have a few extra shims, like anything when switching belts you will need to check your deflection and make some minor adjustments. I think I had to add or remove a .030 shim when going from the OEM to the Dayco belt.
I have about 500+ boosted miles on my current belt and it looks good as new.
Thunder
I know nothing about shims or honestly how to achieve proper belt deflection. It engages around 4000 RPM and that's about as far as I have ever gotten with clutches on sleds..