GuyRule #119.7: Complete Unbuckle at the Urinal
There are only two ways to use the urinal, the Coordinated Guy and the Committed Guy. Now, the Coordinated Guy knows just how to wriggle his equipment out for the job when only using the zipper for access. However, he must be careful to minimize both (a) the length of time fishing for the equipment and (b) the amount of hip gyrations to prepare the equipment for extracation. Any excess or unnecessary time or movement immediately make this Guy suspect as to his intentions. Other Guy Rules apply, such as handling tools firmly and confidently, get in and get the job done, etc.
The other is the Committed Guy. Now this fellow, probably for reasons of lack of coordination or grace under pressure, commits fully to the urinal process by undoing his belt, the snap at the waistband, and the zipper, thus allowing free and easy access to the equipment. While looking silly at first glance, the Committed Guy has to be appreciated for (a) committing himself fully to the task, and (b) finding the perfect balance for maintaining control of the equipment, flow & aim while still not dropping the pants down to his ankles (and thus into the ever-present tidepool of urine from the splashers and rushers). However, there is probably a high correlation between the Committed Guy and the liklihood that he lived at home too long with his mom, and you can bet your ass that he'll be a handwasher 100% of the time.