I know I'm just a lowly female, and you didn't ask for a female perspective, but imho, large is anything over average (having had both large and small husbands), and I can tell you that what is most important is having an unselfish, caring lover, not size. It just turned out in my case, that my well-endowed husband (9"x7") happened to also be an unselfish, generous lover who saw that I was satisfied. The small one (4 1/2"-5" - started out 5", meds made him 4 1/2") also was a selfish lover who had 5 minute sex to get off; never cared or asked if I were okay (Didn't have an orgasm given to me for 29 years but stayed faithful. It's no wonder I couldn't learn to love the guy.)
So the upshot of this loooong post, guys, is learn to use what you have and be generous in the use of it and the satisfaction of your partner. My 2 cents from a female point of view. Sorry for the intrusion.