Yes, well I have just been researching, and have made some interetsing observations. Having a curved penis will give you an advantage in some positions yet a disadvantage in others. An upward curve hits the g-spot better in missionary, yet a downward curve hits the g-spot better in doggy. I guess most girls like doggy quite alot, so maybe a downward curve is good? I think it would maybe be best to have a straight penis after all, then adapt your position to target each wall, as apose to being great in some positions, but limited in others.