I rode SPDs for a year on a road bike and I never learned to pull, it just felt awkward and I saw no benefit. However, the combination of cleats and bike specific shoes seems to be more efficient at transferring pedaling energy, but since I was never a competitive rider it didn't matter to me much. I use knobbed BMX pedals and I get tons of grip, I never have problems with sliding off the pedals even in snow and rain. I understand though that most people would be unwilling to put BMX pedals on their road bikes I know I'll have a dilemma when I build up my Kona Sutra frame.

Adam