The curve question makes me think of two particular men, both with large cocks and both curved. Man #1, curved downward with 9", could get deep throat if I kneeled in front of him and let it slide down following the curve of my throat. Man #2, curved upward with 8.5" and could only get deep head if we did things in a 69 position. #2's curve was such that it would poke him in the belly when all hard. They both came great. The right position seemed to be the key to success.