The thing with 0 standover height is that it gets to be a pain in the butt everytime I stop at a stop sign or red light which happens often since I live in an urban environment. I thought I could ride a 52cm, but I've come to the conclusion that I need a 47cm, maybe 48cm. Max 49cm.
I could just rest the ball of my left foot when I stop with a 52cm bike with 30.5in standover.
People say that top tube length is more important than seat tube length when buying a bike, but I have to say that seat tube length is very important especially if you have short legs like me. Unless the top tube is extremely long/short in comparsion to the seat tube, all one has to do is switch out the stem in order to get a better fit.