my pug is about 59cm and it fits great. the 61cm just felt like a horse, i wasn't overly stretched out or anything, i mean it would have done me fine i'm sure but it just didn't feel very nimble and it was playing on my mind.
i'm about 6ft 2 and a half i reckon, and (i think) i have short-ish legs, standing over the 61 the crotch of my jeans was on the bar.
also, when on the 61 the seat wasn't as high (obviously) and the angle of my body felt too relaxed, i felt like i was sat up like a sail.

anyway, i'm happy now.