What kind of bikes are we talking about? Upperend racing level machines? Midlevel "Sport" bikes or cheap bottom of the line bikes?

all of my road bikes mount sidepulls and they all work great as far as I am concerned. I think performance is somewhat subjective to the rider and what that person is used to. Personally I think the idea of being able to 'Stop on Dime" is overrated. Granted there are times when a panick stop is in order but in recent memory I can't think a time when keeping my wits about me wasn't more benificial than having brakes that may stop me 2 seconds faster.

Only one of my bikes mounts DP brakes and that is more a fashion statement as I wanted all black components for a change of pace. Otherwise my old single pivots do great service even the "cheap" Suntour (DiaCompe) Alpha 5000 brakes on my '87 Bianchi.