Do the 23's flaten out on so much on the hybrid rims to make even more tire touch the road then with say the 25s or 28s?

I just stopped at the bike shop and picked up a set of 23's for my Trek 730. I'm wondering if maybe I would have been better off picking up a set of 25's or even 28's. I am currently riding ... 35's...I think, not at home at the moment.