Most of us don't wear skin tight jeans.
I don't. I wear standard jeans. Maybe slim fit sometimes, but definitely not skinny. I'm 5'9" 160-165lbs. Certainly not fat, but not what I'd call skinny either. I've definitely been lighter, but I prefer more form fitting pants, and so classic slacks are no good. I like some slim fit slacks/khakis but sometimes they're on the tighter side and so a tailored cut is better. I wouldn't say slacks in general are too tight. It's jeans that usually end up being a bit tight when I was carrying my 4.7" Windows Phone.
I can see how girls can never fit phones in their pockets though. My gf actually gives me her SGS3 a lot which ends up being annoying because now I have to stuff two phones in my pocket. Especially if we're out at a club/bar, for me to hold a camera on top of that? lol no pockets left....
I wouldn't say the SGS3 is unusable. I just feel more bulky/clumsy holding it. It's pretty ergonomic for its size, but my most extended use could be on my 4.7" Titan 2, and I definitely prefer holding my SGS2 to that.
With that said I do love the SGS3 screen. When I look at my SGS2, I go damn this thing is small (I freak out everytime I pull out my iPod Touch in my car to enter in my gas log when I get gas). It's tempting to get an SGS3, but at the same time I want to see the next Nexus. I think 4.5" would be a good compromise size.