My problem is not so much with the need to select the Vent to enter/exit
(Though I don't like that either) but mostly I am concerned about the loss
of control, and mostly while exiting the vent and entering some room...
Hypothetical Situation:
There is a room with one door and one vent opening on the ceilings, and there
are few marines camping in there ready to kill what ever try to come through the
door... So I decide to try and sneak in through the vent at the ceilings...
In AvP1/2:
I crawl through the vent and to the ceiling of the room with the marines, I then
crawl to the wall behind them and down to the ground and then and... rip them
apart of something... or die trying...
In AvP(3):
I crawl through the vent to the point where it opens up to the room with the
marines and I activate the opening... My "auto pilot" kicks in... It moves my bug
through the opening and with my luck drops down to the ground and parks my
bug right in front of those marines... followed by some alien dying screams...