I wonder how much difference it really makes. Lighter wheels will definitely help you accelerate but, once you get up to speed don't make much difference. On the other hand, every ride starts at 0 MPH so your perception in the first 1/4 mile or so is they make more difference than they really do over the course of the whole ride. It's still more fun to ride with light wheels, for that matter, it's more fun to ride on a light bike.