I recently purchased a Bianchi San Jose. I'm 5'6 and have a 30 inch inseam. I went to a very reputable bike shop (rated very high in the city paper) in my city to check out the San Jose. I liked the look and single speed is very cool. I tried out the one they had on the floor (52cm). I though the standover to be a bit high because I have been reading that you need an inch or two for standover on a cyclocross bike. Mind you that the last road bike I had was almost 15 years ago and I don't remember the size or the fit as I was pretty young then.
In the store I stood over the bike and lifted the front wheel up about an inch, but not more. The sales person said that the bike looked about right. When I got on the pedals and put my hand on the bars, the guy said that it was the right fit. I was excited and took the bike for a test ride. The ride was awesome. While I am on the bike riding, I don't feel cramped, my leg extension is good, I don't feel like the bike is too big. I have even taken it off some simple off road trails and the bike feels great. Riding is not the problem.
Here's the problem though. When I stand over the bike at a stop, I can stand over the bike safely without hurting my self. There is a little bit of room. When I stand over the bike without shoes, my "stuff" is resting on the top tube. Again, riding is not the problem and I am able to stop put a leg down and take off again without trouble. However, I am wondering is this size is ok. I sat on a 49cm Bianchi Pista and it was too cramped. I sat on a 49cm Bianchi Veloce and the standover was good, but I felt cramped especially when I crouch down on the bars. In hindsight I am wondering if I should have waited and got the 49cm, but I was excited and bought the 52 based on the ride.
Sorry this is so long, but I've been thinking about this for awhile and I've been riding the bike alot trying to figure out if I can find problems with the ride itself, but I cannot. This standover thing irks me.