Well I can tell you that of the extra's that I've seen the gag reel is brilliant and the extended scenes/man out of time/alternatives were very interesting.

In the UK - and some other places - Coulson's last scene is edited so that we don't see the spear tip (sorry, trying to be cagey because I know they're people on this thread that haven't seen the film). It isn't much and they've done it before on other films - the UK's version of the Hunger Games, for instance, is different to in the US with editing of similar scenes. It isn't a huge change, but censorship or different countries getting different versions makes me twitchy.