I think the reviews embargo is still in place but people are breaking them.
Here's from Time Out London
Calling ‘Iron Man 3’ a mixed bag doesn’t really do justice to the heady peaks and interminable troughs in this scrappy but overwhelmingly likeable superhero sequel ... The result is a film which never settles into a comfortable groove. It tries to be an angsty ‘Dark Knight’-style game changer, an ’80’s-throwback action romp, a nudge-wink pastiche and a CG-fuelled spectacular. It’s undeniably entertaining – and worth seeing for Kingsley alone – with the misfires never fully overshadowing the moments of glory.
Some random blogger reviews -- them0vieblog
A podcast interview review from metropolis.co.jp
at a Tokyo screening --
Q:Would you recommend this movie to other thinking adults?
A: I am going to. If you're a fan of superhero movies, this one is way above average.