Do not expect a story: It's got basically none.
Do not expect characters: They are stereotypes you have seen a thousand times already.
But that was to be expected.
The movie lives by (literally) large scale action scenes, does actually incorporate 3D, and shows how giant robots and aliens look like should you use the present technologies possibilities, instead of guys in suits. And they can look really cool and impressive that way
(Oh yeah: And I considered some of the Jaeger interior shots getting close to being sufficiently detailed
All in all: Turn your brain off, and enjoy the impressive pics