When I 'shop' for bikes, I generall populate my short-list with bikes that meet certain fit criteria - usually just minimum effective top-tube and head tube lengths.

To properly compare the fit of two different bikes, you need to consider wheel size, fork length, and bottom bracket drop, and head tube length to get the full picture.

The most frustrating thing is, in my search for an extra-large-fitting 700C wheel single speed mtb frame, I have found several manufacturers who make four or five frame sizes but all have the same 4"-4 1/2" head tubes! So all 5'6" people ride heads-up cruiser-style, and all 6'5" people ride ares-in-the-air racer-style!