I have low hangers and they are a pain...literally. Sometimes I sit down on them, especially when getting in and out of the car. I often have to reach down and lift them forward before sitting, which can be awkard at the office. They also get in the way when trying to exercise, even something as simple as walking or hiking.
It's also hard to find comfortable underwear--boxers offer no support, but the only way I could squeeze into briefs is if I shoved my balls up my asshole. (Actually, I can't really do that, although I've seen it done.) Boxer briefs are OK. (I actually found this forum while searching online for underwear. I'd like to find some supportive briefs that aren't too confining.)
I'm envious of guys whose scrotum tightens up during sex. It seems like they have stronger ejaculations. I saw a porno once where this guy's balls kept lifting up as he was fucking. You could tell when he was getting close because his balls kept going higher and higher so that when he came, they were on top of his dick. I thought that looked pretty cool and I wish mine did that.
Someday if I ever have money, I'm going to find out if there's a surgery to tighten the scrotum, or at least lift it up a bit. Just an inch or so would probably give me a lot more comfort.
As for balls slapping around during sex, I can't say as it's been a big problem, but for me there's no benefit, either.
--Meniscus