I like it VK, still think it'd be better as an secondary MS latter on, but i like the way you balanced it either way. 

(Im assuming that it no longer has the grenades and grappling hook, seeing as they weren't relisted?)

Edit: Kinda curious to know how a pilot as young as Terra came to possess such an powerfull machine in the first place though. Especially if she has yet to do anything spectacular to cause her supirors to pay her special mind. The Zeta really seems like something Aero would have piloted by a proven inidividual, but thats just my two cents.