Funny, my loadout is similar to both of yours too.
DMR/BR: UNSC weapons are the only weapons to get ammo from ammo creates.
Plasma Pistol: Elite-be-gone
Jetpack: Moblity reasons
Fast Track/ AA Efficency: Dat XP; for more AA use
Dexerity: Reloading dem power weapons are quicker.
I guess great minds think alike, eh?