Ok if you honestly think Fafner is better than Rahxephon, then you're out of your fucking mind, and should probably abstain from ever giving an opinion on a show for the rest of your life. Fafner had a really awful first half, but it did get significantly better, and more or less redeemed itself in the last 3-4 episodes (specifically ep 23). But, creating characters with a specific intent on killing them within a few episodes, just to get some sort of emotional reaction from the audience sucks, just so we can watch these kids grovel and lament theire fate and cry, lets wallow in the angst!! The character development drastically improved in the second half, characters became likeable, deaths became impacatful. When the new writer showed up, the difference was definitely notable.
For sure Fafner had an Excellent soundtrack and fantastic OP/ED (Which aren't by kotoko, duckroll

) no denying that.
But the mech design was HORRID. Holy shit, although a few of them were "neat" the majority were just awful. Lanky, unoriginal just...ugh
If the show had kept its pace from the first half, I'd have no qualms rating it an F, but the pick up through the second half elevated it to a solid B-. This show had me pretty conflicted throughout, but whatever...I was pretty satisfied at the end, and probably looking forward to the OVA