He didn't really figure out anything most of us that ride don't already know.

First, the delta between a 20lb and 30lb bike doesn't matter much once you add in the rider weight and other stuff you're carrying.

Commuting time is dominated by traffic control if you ride legally.

If he went for 50 - 60 mile rides with his friends through the countryside on the weekends at 16 - 20 mph, his experience would be greatly different.

At lower average speeds with constant stop and go, it's more important for the bike to be adjusted and well lubricated.