I just got a hybrid built on a Soma Double Cross frame, and the fit is almost perfect but I can't get my saddle back far enough. Even with an offset post, I find myself wanting the saddle back another inch. The biggest comfort/efficiency factor on my last bike was the same. It comes down to the angle between my hip joints and the pedals, when the seatpost is at the right height and my back and arms are comfy. Which is a long way of saying, I wouldn't count on being able to fix a fit issue with a longer stem. It's all just so personal... That's my two cents as a complete newcomer to the forum. Good luck!