Sorry, yes ANOTHER frame size thread. I had something I was curious about and couldn't find the information elsewhere and figured I'd ask regardless of it being another frame size question...

...anyways, since the weather is nicer my wife and I have been trying to get out and ride as much as possible. I have noticed a trend riding around downtown SLC here, even in the small city that we are: people are riding some small frames. Now I'm 5'10 and an inseam of 32.5. I was told to ride a 56cm bike, which I do. Honestly it does feel comfortable but big (and maybe I'm just used to riding BMX when younger that anything above that feels big). We stopped to talk to a guy the other day that we had met on a few occasions when riding and this guy is probably 6'1 or so and I swear that guy had to be on a 54cm frame, or smaller. The seat was high in the air and the bars slammed. We'll I started paying more attention to it and have seriously noticed that people tend to be rocking a much smaller fit than I am. Is this that people just are not aware of proper sizing or is there some advantage to running a smaller frame?