Are you sure about the lack of flex? When I'm hill-climbing on an M-type there's lots of flex and it looks to me as though it's coming from the base of the stem. Of course the lower the bars the less flex as it's amplified with distance from origin. I figured that if one used a combination of riser and aberhallo to extend the bars to the same height as the M-type the flex would be more or less the same.