I'm incredibly happy we finally got to lay our eyes on these bad boys in action. I've been really wondering what kind of combat role they would fill since the others seem a bit more predictable. The Cabal seem bulky and reliant on weak points in their armor/shield configuration. The Hive likely will have runners and other more traditional zombie class agents and the Fallen have displayed a more tactical combat style, probably aiming for that "realistic player vibe" that will try to really out-think the player, much in the fashion of the elites from Halo. But the Vex? They look like they are literally going to be swarming you in close quarters, almost always present around you as your crew battles to keep them on the edge of the circle. It honestly reminds me of some of the best feelings of fear you can get from Halo's Library level on legendary. Everyone tends to groan when they hear about that level, but Bungie achieved something spectacular gameplay wise. The Flood were constantly surrounding the player, driving them to keep moving or they'd be overrun in one singular location with no means of escape. Sure, it grew tiresome, but that was partly the point. I hope the Vex fit a similar role, though obviously refraining from growing tiresome to combat. They seem different enough, but still realizing that fodder like role, simply trying to wear down their opponent with numbers. And hell, they are time traveling robots...their back story just sounds badass without any more details.