I think you're overreacting. The AvP1 Aliens were badass, sure, but the AvP2 ones just ate shit and died all the time. These ones are actually faster than them and clearly act more intelligently. For instance, they seem to choose attack paths that are covered (which you might've noticed was foiled by convenient explosive barrel placement). In other videos, we've seen them, again, take routes that are covered by darkness or objects and kill AI Marines in one hit.
In addition, they don't announce their presence like in the previous games. In both the Predator and Marine videos, we've seen the player take damage from behind with absolutely no warning. In both previous games, the Aliens were much louder as a general thing and in AvP2, rarely (if ever, to my memory) attacked you from behind.
EDIT: It'd be cool to witness some Alien vs. Predator fights as a Marine in SP, especially if Rebellion break away from the cliche and don't have the Predators utterly dominating the Aliens.