Seat tube angles. I weighed by bike and me a few years ago and established where my center of gravity is relative to the bottom bracket. Compared that to my old racing bike with handling I loved. (Nearly all the bikes I've owned since are light in the back end and scary on mountain corners on poor pavement. That race bike was rock solid.)
This gave me the ideal weight percentage for the front and rear wheels. For good riding frames, I need both wheels forward. I also like shorter wheelbase frames for their feel; always have. So, short chainstays. If I keep the seat tube straight, this means very close tire-seat tube clearance of a steep seat tube angle. I haven't gone curved yet so i have a bunch of bikes with steep (74 and 75) angles and big setback custom posts. Odd, expensive, but the ride is there, the fit is there! I love it (though I'm talking curved post if I do another).
I had my Mooney built after my head injury as a do-everything bike that would never see a racing number. Peter put long chainstays on it for pannier clearance. Biggest complaint (that I kept quiet about to Peter) was the light rear end. Until - I set the bike up fix gear. Now that marginal mountain corner speed is impossible. Pedal strike happens first! Absolutely love the ride now! Love that I spec'd horizontal dropouts - just so I could. (The bike has done everything over its 41 years. Fast club rides, tours, gravel (before it was "'gravel", very long days ...)