I think you're not qualified to comment on which would bring you more accomplishment if you haven't even completed one of the activities in question. Just my two cents.
I don't mean that to be offensive, nor do I even necessarily agree with the OP. I just think that you shouldn't make a statement about which weapon would give you greater gratification when you haven't even earned one of the ones being discussed here. Same thing with the guy and his "raiding buddies" - does it matter that that it took less time to down AS12, when the skill floor is CONSIDERABLY higher, beyond a doubt? Yes, people can buy clears. Incidentally, people could buy their way through the materia step, or also buy bot programs to bot parts of the relic step. Neither claim holds much merit over the other.
I think that for the people who raid, not being able to customize their raid weapon really is a kick in the teeth, given the effort they put in. Top-end players will put in time for the thankless, boring relic grind just for that extra 1% efficiency, and I don't think that's fair. If the devs are going to continually balk at making the relic questline challenging, they should at least offer a customizable weapon alternative for those skilled enough to complete the hardest content in the game.