i'm between 5'6 and 5'7, i think my cycling inseam is somewhere between 30-31. i was between sizes for this bike (50 and 53). went with the bigger one!
having the slightly larger frame makes all the difference if you're trying to fit frame bags etc.
i've stripped the frame btw, so the frame+fork only is available if you're interested in purchasing (or trading for wheels!)
Huh, I was thinking about the blue one, but I could maybe be persuaded. How much cash for the frameset?