I recently had the opportunity during a flight test program to actually stall a 400...not an approach to stall but rather a full fledged stall. With a weight of about 95000lbs, we were well under 90 kts when we experienced the buffet etc and the aircraft was fully controllable...just kind of mushy. Provided me with great confidence in the 737, as you have to have a serious lapse of brain matter to get yourself in this situation unintentionally.