Originally Posted by
Phil_gretz
4) Geometry - as has been mentioned, most traditional road frames are not designed with [flat] bars in mind. So, you'll be using the stem to correct for what will put your torso at the right angle and you hands at the optimal reach. This is separate from cost (1), as the answer may take several iterations to solve to your satisfaction.
Uh, that's what stems on road bikes are always used for.
I do not agree there is any necessary difference in geometry for flat or drop bars. There is as much diversity in drop bar geometries as there is in flat bar geometries, and smart buyers will need to choose the frame that best serves them regardless of bar configuration.