The movie's main selling point is that the same evidence you claim makes Ava 'human' can be the same evidence used to prove she is only a program. It's impossible to make a foolproof argument for either camp, so there is no right or wrong answer. Whether or not she is sentient doesn't matter because as far as the movie goes, the audience never truly finds out. It ends before we ever get a definitive answer. The movie has to end that way to create the endless debate of 'program or sentient?'. The way the story is written supports your opinion, just as much as it supports an opinion almost completely opposite of yours. I think this makes the movie well written and popular (because it instantly polarizes most people), but also presents a major flaw: the story has to end before that definitive line (program or sentient?) is fully crossed. The resolution to this question is never reached, so I felt unsatisfied.

And so to me, the movie ends right when it gets most interesting. That's the problem with a story written like this one. In order for the selling point of the movie to work (both extreme opinions placated), the movie is forced to end on a resolution that doesn't feel like a resolution at all. And I'm not saying that a lack of resolution is a bad thing. Lack of resolution is the selling point to a lot of artwork and stories, and can be done very well to illicit certain responses from the audience. It's just that this particular lack of resolution felt boring. No wonder you rooted for Ava, because Nathan and Caleb's repetitious philosophy 'debates' feel almost as hollow as the ending in terms of definiteness.

And of course, the 'artsiest' response is that there is no resolution because we still don't know how we would accurately test and separate a human from an intelligent replica AI. To those people: fuck off, you unimaginative fucks.