My winter bike, a 25" Raleigh Rocord, has stem shifters & the rest of the fleet (63 cm & up) on the down tube. Obviously I'm on the tall side. I find my hands just fall right onto the DT levers, feels natural & intuitive. On the stem it feels either as if I'm doing half a Funky Chicken, one arm out flappin' in the breeze, or I'm giving myself abdominal thrusts.

I set up my step daughter's mixte with upright bars & cruiser seat & the stem bars work beautifully there