ive been riding the 700x32c (1 1/4") ones for years and many thousands of miles and they dont feel any slower than the 23c durano plus' i had ridden previous. they are my favorite tire. they do a great job of smoothing out the ride and allow you to access a lot of places that skinnier tires dont.

i have a pair of 650b wheels in the works which ill be putting 38s and 43s if they can fit in the frame, i dont expect those to slow me down at all.

hell, my ECR with 29x3" knobby tires still seems fast and thats just a SS. a "bump" for that thing has to be a difference of 4" or more in road surface