5'8" with a 32 inseam and ride a 52 and 55, but but have the same 55 cm top tube.

Some people do. My exception is a Lemond 55cm. I'd have gotten a 54, which sounds right but its only made in odd sizing.

i'm 5'9". my friend is probably 5' 10" or 11" and has a 55cm GTB which i rode. it was kinda big. my workhorse bike is a 52cm (!) with the seat tube up allllll the way. it still feels a little small with the high seat post. i'm growing really fast right now so i would normally opt for a 55cm for my next frame (i fit a 54 now). but i'm going to be running drops on it, so i'm going to get it in 53cm. my advice would be to get a slightly smaller frame than normal if you're planning on running bullhorns or drops. quite a bit of fit can be adjusted with your stem length and angle plus your seat height and cranks.

also my inseam is about 30". i have a long torso and pretty much normal legs.

Bike #1 - 54.5
Bike #2 - 54
Bike #3 - 55

i'm 5'7 and i ride a 53cm kilo.
my friends have 50cm leaders and i think it's a bit on the small side.
i rode my friends 55cm leader and i thought it was perfect.
i guess i have longer legs and a shorter torso.