Can't help chiming in with some comments - hope you take them as constructive criticism.
1) The vehicle is WAY too clean and not nearly cramped enough. Where is all the extra ammo, the chow, water, kevlar blankets, AT-4's, night optics, cammie nets, etc., etc., etc. There should be a TON more stuff back there.
2) In my opinion the purpose of a diorama is to tell a story of some sort with the model and figures as key elements of the story. What is the story here? Two guys are kneeling in semi-tactical poses. Two guys are standing doing...? and why is noone on the MK-19? I'll tell you something - I spent enough time in Iraq to know that there would be a gunner on that weapon system.
3) As has already been pointed out, the cammie pattern is all jacked up.