I went to see it on Saturday, with my son. It was probably about as good as I expected it to be - which is to say, not terribly.
Obviously, all movies require suspension of disbelief to an extent. This makes it kind of awkward when you know too much. For example, aeroplanes just don't fly like that. The crust is actually already floating on a molten layer (the mantle). The surface of the earth won't reposition itself by 1200 miles in an hour or so - or if it did, it certainly wouldn't be predictable. And if neutrinos did suddenly start interacting with matter, the significance of this wouldn't be explored first of all in government, but in the pages of Scientific American. Heck, while we're at it, thousands of feet underground there aren't significant changes in temperature from day to day.
So in geological and physics terms, it was mumbo jumbo. Likewise in technical terms. For good measure, the metaphysical references were nonsense. The "conspiracy theory" bits were the usual teasing on the vague paranoia that tabloid journalism breeds.
On top of which, the leading characters were pretty standard one dimensional heroes and villains. The writer, who missed his children getting older and ended up losing his family to a plastic surgeon (oh please!). The Russian oligarch who is entirely self-interested, but redeems himself partly at the end by saving his children. The impoverished but brilliant scientist, whose death through the indifference of the system is the pivot that turns people from behaving selfishly to selflessly. The cutesy pet. The bureaucrat working for the "higher good" who becomes a monster. A parade of characters which could have been ticked off a list, all with limited background, all of whom come to pretty predictable endings.
The special effects were spectacular - though again, overblown. To be fair, I suspect that this was the major reason the film is likely to be of interest to its target audience (which is to say, boys). There must be an element of sociopathy in somebody who is prepared to document the destruction of ... well, the world, basically, and portray it in such vivid detail. I mean, I have issues with the concept of Las Vegas, but I wouldn't want to see it trashed like that.
The moral of the tale - that being human means caring for one another - was fair enough. It was not substantially better made than in (say) The Emperor's New Groove, or Over the Hedge, both of which had the advantage of better jokes. It's worth pointing out that this moral is preferable to the other stable of sci-fi blockbusters (please distinguish good science fiction from this genre), which is that an unthinking devotion to your tribe is what is needed, especially if that tribe is the United States. The film reflects perhaps a broader vision of the world than has been common coming from Hollywood. However, the vision of the rest of the world - and even of the US - was frankly still pretty cliched.
If you're happy to watch spectacular special effects and aren't bothered by thinking harder than cliches demand of you, then you'll enjoy this film.