For me it's the BC that got me started doing the elevator descent. The first time I wore one that's what everyone was doing so I followed suit--I had no experience with a BC. Now that I've figured out how to fit my backpack/small wing configuration into my carry-on and no longer need to bring a checked bag just to accommodate a bulky BCD I'll likely revert back to the duck-dive. I do think it's pretty cool, though, to drop down to the bottom at a rapid rate and hit the "add air" button just before hitting bottom and end up a foot from the sand, perfectly neutral, spread-eagle, just like Tom Cruise in Mission Impossible (when he broke into the CIA or whatever it was).

Kinda like jumping out of a plane with a parachute only I don't go "splat."