OK, I know Chrome-molly quill stems are sort of weird from a stylistic perspective. stuck somewhere between classic and contemporary. It strikes me though that they may just be some of the stiffest quill stems out there at a decent price. There are some nice ones out there. What do you folks thing of them styling aside? Is a good tig welded cro-mo stem generally stiffer than a cast aluminum one?

Not necessarilly. Steel actually flexes more than aluminum, until aluminum wears out. Then it breaks. But you have to go through a lot of fatigue cycles before that happens. But steel doesn't really get weaker with time. But you have to make it beefier to have it have the same strength out of the box as an aluminum stem.

As far as i understood it the reason that aliminum frames are so stiff is because of over-sized and thick walled tubing. i ride steel bars and stem and it is stiffer and quicker on the pick up than anything aluminum i have ever ridden.

Volumetrically, steel is stiffer than aluminum. So a steel stem will be stiffer than an Al one of similar design. TacoPropelled is exactly right about relative frame stiffness.

This is why early mounain bikes had steel stems rather than aluminum until they went threadless.