Saw this again at the iMax yesterday, was fantastic!!
Oddly, the extra 4 minutes of the film all seemed to be people based, the only transformer extended part I remember was Optimus first transforming and a possibly a few more seconds of Bumblebee and Barricade fighting (though not sure about that). Seemed a bit odd, thought they would have upped the special effects for the huge Imax screen. Still loved it