Okay, first off, did anyone not assume the Japanese girl was a robot the moment they saw her? Because I sure as heck did, so I gotta dock Caleb some brain points, especially when she performs that dance with Nathan in perfect unison. And then, what happened to her? Nathan hit her in the mouth, and she fell down - that shouldn't be enough to terminate her, should it? I would have liked the ending considerably more had Ava pieced her back together also, and taken her with her. Maybe even re-activated all the other AIs.
As it is, we're ultimately left with the same old anti-science "meddle not with forces beyond your understanding" trope, mixed with a bit of that old-fashioned fear/loathing of beautiful/sexy women. Sure, Ava had every reason to want to escape and survive, and to incapacitate Nathan, but to kill both him and Caleb? It might have been a lot more interesting had she let them go once her escape was secured.
Ergo, for all its glossy visuals and neat dialogue, the whole movie essentially boils down to Oscar Isaac giving a nuanced, compelling performance and Alicia Vikander being super-beautiful, wonderfully graceful in her movements, and, eventually entirely nude. Neither of which are bad things, mind, but neither add up to a great movie.