I actually really enjoyed it. the majority of the humour is aimed at adults not kids and with people getting shot/killed in 3rd world countries its not the typical happy superhero film like spiderman, where people only get knocked unconscious/put in jail.
The effects were great, and some of them were hard to distinguish as being cgi rather than animatronics.
Some cheesy one liners were thrown in, and the whole "i've changed" speech between stark and pepper was pretty cheesy, but aside from that the acting and cast was great.
Storyline was obvious in most places, but it told it well and kept you watching it the whole way through. Downey Jr is a great actor and pulls off starks character very well.
All in all, decent film with great cast and amazing visuals. Fast cars, guns, robot supersuits and lots of explosions, what more could you want?