Watched it yesterday.
Pro's were the visuals, I watched it in 3D IMAX in Manchester which is one of the biggest screens, really cool but didn't hit me quite as much as the first time around, I wasn't as impressed. The action sequences were also really good.
In terms of cons, I was a bit miffed how depressing it was, it really tried to drill into you that "Humans are bad". You could tell it was more of a political message with the Whaling story and to be honest I watch films to escape from reality, not be reminded of it, so it was annoying. I felt some of the scenes could have been cut although it wasn't that bad given the length, it did kind of fly by.
The kids were so stupid. It was as though their only purpose was to get themselves in danger to advance the plot.