I've seen tons of divers, but very few broken plastic buckles. I have seen two bright and shiny SS buckles that looked good, but would not cinch properly. Both had a major manufacturer's label on them too and they would get loose without even any depth change. A moderate pull and they were slip sliding apart. At least with the plastic buckles, you can easily see when they're broken. Not so much with the SS. Complacency and laziness are the main culprit with gear that fails. If you're too broke to pay attention to your gear before, during and after the dive, then find another hobby!
I will say at this point that I do love my shiny SS buckles on almost all my gear. It's not like I'm hiking the Appalachian trails and looking to cut every once. But then, I'm not afraid of a plastic buckle either. How can you lose with it costing only a dollar? Heck, buy a new one every year if that will meet your needs.
