I don't like a concept of a Praetorian. There I said it!
Awwwwww! 
I like them, if only to give the xenomorphs some variety.
Yep! I love the Praetorians too. Alien games need variety. It's REALLY boring fight the same enemies over and over again... personaly i would love to see a giant alien-spider in the game 
Oh no, you didn't.
It's boring to fight the same Aliens with the same AI again and again.
AvP2 had Aliens that just ran after you no matter what. (Not just the Aliens). There were moments when the Aliens to tricked you, but that was scripted.
AvP2010 had Aliens that spawned, jumped and tried to attack you with their claws in mid-air, just to die for lulz.
This game offers intelligent Aliens that can be appropriate challenges, instead of horrendous Aliens emerging from horrendous animals/ideas.