It's not just being hung that leads some of us to go commando. There are several things for me. Before I mention them I will say that if you have trouble wearing underwear like me then there's no doubt that Obviously for men, Zakk jockstraps, bumgear sheer underwear, and the like are the most comfortable. And sometimes whether public speaking, your wedding, etc.. where having your pecker laying across your thigh in almost plain sight of a group of people just is bad manners and taste. But only maybe one or two days a month do i find underwear absolutely necessary based on the sheerness of slacks, or whatever.
I am well endowed, but mostly a grower, only about 4 1/2 inches soft, but still need plenty of room in the event of semi's during the day. Also I have naturally thick thighs and glutes. Any type of boxer or boxer brief is going to bunch up 5 minutes after I put my pants on. I have tried lots of brands - they have all bunched up.
You do get to where you enjoy hanging loose believe me. Most all standard briefs are just too constricting, but part of that is that i have a rare condition called polyorchidism. I learned how rare it is when my doctor gave me a testicular exam about 10 years ago. My extra ball has it's own complete plumbing. And it is roughly 50% bigger than the other two which my doctor described as a little above average size. So the third one is really big. I have been to huge clinics for ultra sounds, exams, etc. They photographed my junk 1000 times in two large city urological clinics near where I live. All in the name of 'research'.
I have zero modesty. So while i don't find my junk all that pleasant to look at, it is centerfold material to urologist (lol). Every doctor i see wants to examine them. It gets annoying but hey what to do? The most uncomfortable thing is when there's four or five of them poking around like they've never seen balls before. It's not really that different - there's just three of them instead of two?
Long story....they are very big combined, with my cock sizable also... commando is just much more comfortable. I think i would go commando just because of my legs and ass though, even if my junk was average sized. I am very thankful to the underwear and jock strap folks who have designed products with bigger pouches.