I'm lucky I guess. I have enough bikes/wheelsets that I had the same brand of tire from 23's to 32s on different wheelsets. I could swap them out on the same bike, use different pressures, side by side. For me, there's not much of a difference. Maybe some between the 23s and 32s. The 32s feel sluggish. I also realize that at 5'8' and 200lbish, a typical frame is going to ride less stiff to me than to the typical 5'8" 120-160lbish rider. Heck, the tire size might not even matter that much to me on gravel, if I rode gravel. Come to think of it, I did have to cut though a section of gravel one time on a route I was riding. I was on the 32s at full pressure. Plush enough. I usually buy the cheapest size within a particular brand.