I have an 80s Miyata touring bike that I use as a commuter and for riding around the city. I like a fast, smooth ride. It came with 700x25 tires, but the bike shop recently replaced one with a 700x28. Believe it or not, I notice the difference (doesn't glide as easily but could be because the tire tread). My frame is barely my size, I barely clear the top bar, and another bike shop recommended 700x23 since that size tire is actually smaller than the 700x28s.
My questions is: would a 700x23 tire be suicide being that I ride it in the city for commuting and it's such a thin tire (ie. less stable)? Why would someone use 700x23 vs. 700x25 or 28?