I have 23s on one of my rides, and 38s on another. And , of course, they are VERY different.
38s:
pro -better ride quality (comfortable) on the streets I ride on
con -lots more rolling resistance making them overall slower

23s:
(basically the exact opposite)

My solution or "what I'm doing next time" is find something in the middle... like probably 28s. I think it would be the perfect compromise.