I haven't decided yet if I want to see this. The premise sounds interesting, but it seems like even most of the positive reviews (surprisingly a lot, considering) mention problems with the second half of the film and some of the plot elements.
Depends on how analytical and how willing to suspend disbelief you are. I went to see the movie on a lark this afternoon with no knowledge of its premise -and hence no expectations- and was blown away. Came into this thread hoping to see similar sentiments, but it seems either I'm easily impressed, or we Trekkers are a tough-to-please bunch.
Anyway, I loved it.