Boxes have actually been removed. They remain in the standard stormtrooper model, but they've been removed on the AA trooper, as well as a few other minor details to save on the poly count, which was quite high.
Quite a few people have been recommending I remove the guy altogether, which would solve problems with his somewhat unlikely pose... (i was vaguely thinking that it would actually be more comfortable then standing, because he is holding himself as a counter weight to the turret, like in
windsurfing.