If you're sitting on the fence about seeing this movie, go see it.
I won't spoil it, but it's worth seeing and has a few small flaws you can overlook. (The only one I'll spoil is how all the humans speak english, which is a universal movie flaw, it seems.)
If you were going to avoid it because the AVP movies, especially the second, pushed you away, come on back, the water's fine again.