Well I saw it last night, and left the cinema feeling a bit disappointed

Will Smith was really good in it, but the plot wasn't. It was all over the place.
The scenes shown halfway through were of what you should have seen at the very beginning, to understand what had happened and why it had happened (why New York City was such a mess etc) so for the first half of the film you were left wondering wtf was going on. It did keep your attention though.
The film is 99.9% full of will smith, literally, except for towards the end where some new characters came into it and then it ended quite suddenly. It was as if someone else had come along and written the ending. Like the work experience kid

Could and should have been alot better, but I'm still glad I've seen it.