No, it's not too old, it's just shitty. Compared to the original Gundam, Votoms, Macross, or any shows from around that era, Ideon is crap. It has a weak concept and poor characterization. The only portion of it worth watching is "Be Invoked", and only to laugh at the hilarious death scenes.
Evangelion borrowed SLIGHTLY from "Be Invoked", but other than that, is nothing like it. Maybe you should actually WATCH these shows before you decide which one is better than the other.