My dad's shop went with a threadless adapter on his Teledyne Titan and he hates the look of the new stem and, I have to admit, so do I. The stem just doesn't look right on that bike so I'll be installing the Cinelli quill stem back on it.

I'm 5'8 and have stems ranging from 90 mm to 120 mm on my bikes - much is dependent on the top tube length. My Gitane Sprint has the shortest stem and I am pretty compact with it when upright. But I have that bike set up with my clamp on aero bars and do time trials in the summer with it. In the aero position I'm quite comfortable. In contrast, the Gitane Tour de France has the same top tube length but has a 120 mm stem which allows me to stretch out which on longer rides I find more comfortable.