Two things so far i've encountered in the Beta that's gonna take some getting used to:
Maybe i'm just spoiled from other FPS, but god damn does this whole "don't press Sprint when reloading or it will interrupt the reload" shit annoy the hell out of me. I'm constantly finding myself reloading, sprinting away then stopping to only find 2 bullets in my mag cause i'm an idiot.
The second thing, which i'm sure is something i'll see more on live due to it actually making sense there, but 1 out of every 3 Strikes I join, people just bum rush the boss when possible, ignoring all the mobs along the way. Do these people not realize we don't get to actually KEEP the gear we get in Beta? What the fuck is the point of rushing the boss in the only PvE content we have in Beta for gear we won't even get to keep? Shit, kill mobs, have fun, it's Beta for fucks sake.