I'm not sure if anyone's interested, but I'm a soldier and I've used all three of the pistols mentioned in this article (I'm currently carrying a Browning). Here are some advantages/disadvantages for them.
A: Weight helps to keep it steady, so if you're firing quickly then the fall of shot is fairly consistent. People with big hands find it comfortable to hold. It's easy to aim. It's (almost) impossible to break or degrade - missfeeds are normally due to the magazine rather than the pistol.
D: You need a fair grip strength to cock it whilst keeping it and yourself pointing forward due to the powerful return spring ("backhand" cocking it isn't completely safe IMO). Cocking it is slow and easily fumbled, especially with wet/oily hands, so a poor choice for dealing with surprises. Poor safety features mean it's not safe to carry it if it's made ready. Uncomfortable for small hands.
A: Easy to cock. Can be carried loaded and made ready, with the hammer forward, so it's ready in a pinch. Light.
D: The lightness gives it a tendency to bounce about a bit if you're firing quickly, so the fall of shot can rise if you're not careful (and if you've drawn it in a hurry) - this can be countered with a good grip, but you might not have time to think of that. The decocking lever is a bit far back if you've got long thumbs.
Glock (disclaimer: I fired 1 magazine through one of these about 3 years ago, so not as familiar as the other two).
A: Easiest pistol to use in the world as far as I can tell. Fall of shot is incredibly tight. Light. Virtually no bouncing around or rise so you can fire accurately pretty much as fast as you can squeeze the trigger (not sure how they manage this with such a light pistol, must be very well balanced). Large magazine.
D: None that I can think of.
By the way, it's not just "that community" that use Sigs - as far as I can tell pretty much all of the pistols carried in theatre are Sigs - I've only seen a few other people with Brownings. The RQ actually apologised to me when he gave me a Browning to bring over. I don't mind though, I prefer it to the Sig.
By the way, the desert eagle is a joke. It's designed for rednecks and saudis.