This is mine, i have the alacrity for increast casting speed, crit chance, and decent survability, since grav round is one of the bread and butter abilites in this tree that you use constantly. It reduces the caste time of it, and charged barrier reduces dmg up to 10% and use it with your reactive shield, makes you really for a short bit of time. I''m also looking at this from purely a pvp stand point.
lol forgot the link http://db.darthhater.com/skill_calc/trooper/commando/#::e2fe3fe5fe8f13ef5ef11efef4