I really liked this movie. It's the best movie I've seen in a long time.
(that speaks more about how poorly the other movies were, but still it's a great movie)
After reading that it had a disappointing ending I thought it was going to have the typical human scientists finds a weakness that destroys all of the advance race in one shot. Well it doesn't. I liked the ending too.
It's an Aliens attack the Earth movie, keeping that in mind and all the nit picking about realism is just silly. If it does bother you, here's a realism that should really make you hate the movie: There are no aliens.
The whole water thing was a little out there, but I wrote it off as "The news jumping to conclusions". Just look at all the odd ball predictions they had after the Earth Quake in Japan. But even if they were draining the ocean, look at all the measurements with global warming. They're claiming water levels in the ocean are rising at .00001 millimeters every 20 years or so, I’m sure if they have that kind of precision going on, they'll notice that these aliens are draining the oceans.