Um ... not sure what else to say, since the title sort of covers it.
Last Summer I ordered a pair of these from Amazon.com. I unfortunately can't blame Amazon since I neglected to bother with their fine print, and I had just plain forgotten that 501s have a button-fly. So I got them, wore them, and immediately regretted buying them. But didn't feel like returning them. I do think they show off my butt real good though.
Problem is ... normally taking a pee, as a guy, is simple. Walk up, unzip, do my business, and rezip. However having a button-fly brings that effort to an entirely new level. No longer can I simply just unzip when I wear these things. I have to wrangle and wriggle around so they I can unbutton 5---yes 5--- buttons on my crotch. And if I really have to pee, well, it's just that much worse. Then, and only then, will my god-foresaken pants allow me to relieve myself. And then afterward I have to reverse that, buttoning all 5 back up.
Oh what a pain it can be to be a guy!