Y'know, I found that one of my bikes (My Freschi) fits me just perfectly for climbing, flats, comfort - essentially, everything. So when I decide on bikes to keep, I try to match that geometry and measurements as closely as possible. I look at stem length, saddle height (from crank center) and position, bar width, etc. to help inform my decision-making. That said, I prefer a longer, more stretched out top tube: fit wise, I'm supposed to be riding a 58, but most 60's seem to fit me better, especially for climbing, where I prefer to stay in the drops rather than standing. For longer climbs, where I will occasionally stand up, my 58 seems to be a better match up. (However, that is a modern bike with slightly sloping top tube, and I'm not certain how much modern geometry changes the equation.)