I'm actually re-watching RahXephon for the first time, since it was originally released in the U.S. by ADV (who's now a defunct publisher, e.g., non-existent) back in 2003/2004, whenever it was.
Upon my first viewing, I always thought the first 5 episodes showed something that was an original concept, although, it kind of was shades of Tidus (Ayato) and Zanarkand (Tokyo Jupiter) from Final Fantasy X, even if there was no godzilla beast (Sin) destroying it, but it has that whole being separated from your home shtick. Also, the time differential, and the enemy (Mu) actually having discernible identities, much UNLIKE The Angels from Evangelion.
And then, after the first 5 episodes, as far as I was concerned, it was just a rip-off from Evangelion for reasons I won't spoil here. I didn't find the characters memorable or distinct, and I just didn't care about their plights, whatever they were.
Upon re-watching it, however, I recognize exactly how much I never really understood it to begin with, but re-watching it, and knowing how it ends, the plot twists revealed by the end, you understand how things are supposed to make sense, and you recognize the subtle foreshadowing that they make to those twists beforehand.
Actually figuring out character relationships and motivations is what makes the show for me, because it's definitely not the battle choreography; even if the RahXephon finds itself in a jam, at one point or another, it just powers out of it and destroys the enemy in a single stroke.
Aside from that, I'm enjoying it a lot more now than I did the first time around. But I think watching each episode back-to-back, and not waiting a month between volumes, means it's easier for me to follow, rather than trying to draw upon buried memory from a month ago.
I was probably just tired of having to pay $20 each for individual DVD installments that only had as few as 3 episodes at a time. And RahXephon is THEE LAST anime that I ever bought the individual installments of; I've been waiting for the boxset releases since then, which pack as many as 7 episodes on 1 disc.
I also just got Evangelion 1.11 and Evangelion 2.22. I guess they actually re-wrote the anime, and added a new major character, besides just given the original animation a nice, digital face lift, so it doesn't look so dated anymore.
It's amazing: Back in 2001/2002, Evangelion, on DVD, still looked like it had state-of-the-art animation, for something released back in 1995; back looking at it now in 2012, you can definitely tell how aged it looks.
Evangelion is probably the first and only anime I really, REALLY nerded out over about, and actually looked up fan sites for additional info, and even read fan fiction for. So it's one of those things I can never stop talking about.