Consider the empire axe as well, if i was paying i'd get the axe and save some money, but since your parents are willing to pay $600..
well, ive never shot a dp fx, but that would be my choice because what i mostly look for in a gun is how light the gun is and how the gun feels in your hands, and how straight it shoots. I've shot a few etek 3s, and i was not very impressed.. The gun is heavy and has lots of kick and its super loud, the gun doesnt even shoot straight either. I didnt like how it felt in the hands either, and the packaging is over rated.. So my choice would be the FX