I don't believe that there's any difference with a rapid reapplication of the pedal, but I'll check.

I'll check the sliding pins on the rear - the fronts are 4-piston units, so the calipers don't slide (at least I don't think they do).

I didn't figure that there would be an improvement between DOT3 and DOT4. My understanding is that the main difference between the two is boiling point. Several people offered that there's a difference in the "compressability" of the two fluids (from what I remember their comments being). Far as I can remember, within the parameters of a hydraulic system such as found on my car, you can't compress a fluid - period.

Thanks for the input.