I have noticed that penises of greater than 12 inches (and somewhat with the 11+ genre) that erections are not of the rod stiff variety but a more rubbery bendable variety. I knew three 12.5 guys and all were that way even at height of sexual excitement just before ejaculation and all claimed that they were stiff as oak when erect but clearly were not. This may be one slight disadvantage of the trully super long hung guys, inability hydrologically to maintain proper blood pressure that far from the valve at the base of the penis to get the rock hard stiffness of shorter guys. I have also noticed this in the 12 inch porn stars -- some trick photography is used to give illusion of super stiffness but during sex you always get a glimpse of rubberyness whether intra vaginal or oral type. I am slightly less than 11 inches and have trouble maintaining total stiffness all the time as well but can for short periods drive nails as well as the 6 inch guys can.