I've mostly felt it while accelerating, but it's a tradeoff that I'll make to have a more comfortable ride. The difference probably isn't that great, and I may even ride faster since I don't feel as though I have to slow down for poor road conditions, and I may just be a little too "Detail-oriented" or "anal-retentive", depending on your point of view. I still prefer the ride of the thicker, lower pressure, grippier tire to the one that may be faster.