Okay, I can't help myself...
So, now that that's all out of the way... "Hung." It's an evocative term, certainly, and one both subjective and aesthetic. Some previous replies have mentioned horses, and certainly terms like "donkey" and "mule" have also been used to describe the so-called "well endowed." But, even taking a particular, subjective bias in regards to size and turgidity into account, could it truly be said that all men of the same proportions are therefore equally well "Hung?" Let's consider the aesthetic. Does it "dangle", or does it "swing", or does it "sway". Or is it mounted in that awkward, poky-outy way? Certainly, non-phalic genitalia play a part in this, like "low hangers" and the like, that may or may not be in any particular proportion to the member in question itself.
And then, all of THOSE considerations dually considered, let's make a further consideration in regards to form. People mention "girth", as being even more important then "length." But just like length isn't always in a straight line, girth isn't always in a perfect circle. There are those of the the ovoid and ellipse persuasion, walking among us even as we speak. But I say to you, the man with the 6" perfect circle of girth, and the 5" in in a distinct oval shape will have very different characteristics. And the shape and set of the glans. The relative looseness of the skin and/or foreskin, to the quality, distribution, and grooming of hair.
I'm not even going to DISCUSS proper usage, mechanics, style, and such. We're so fixated on sticking it in, getting it off, and then what? Was procreation your objective? Is emulating that model the only thing there is? I can tell you that MY objective has a different focus, but don't think I don't have a good understanding of the factors involved (and I'd doubt that more then a very few men even know WHAT all four female genital-erogenous zones are, let alone WHERE; anterior-fornix, anyone?).
And then, there are the women themselves, if we're taking them into consideration. They vary as well, both in terms of actual proportions, and potential ones. There's a reason the ancient vedics had "divine" guidance, with widely disseminated advice regarding the suitability of various men and women for each other, based on relative size. From my own experience, dealing with men alone, I prefer an arrangement that let's us both get in on the action, and doesn't predetermine a restricted set of activities. Axiom: If it makes me bleed out my ass, then it was too big. Consequently, there is a quickly diminishing return on the sexyness-value of increased phallic proportions. I wouldn't REJECT a man for being of unsuitable size, large or small, but neither would I make any attempt for a specimen of large-then-average stock, because, while there certainly are SOME benefits, I don't want to have to go to super-bottom anal stretching classes, or endure that kind of pain during sex
dick is a dick, and a cunt is a cunt, regardless of the proportions of their namesakes. So, I would say that BOTH parties involved in our tale of the hapless "friend" are out of line, and need to readjust their approaches...