I got this bow from Waking the Beast. I use it on my red mage since I have no other melee job. Mainly used in farming or Limbus. Mostly for fun now until I can cap archery.
Carbuncle prime is the toughest of any avatar fight right now just because anything could go wrong in those 30 minutes you have to defeat him, he's really tricky. I really have seen plenty of interest with people who want these weapons, but only summoners actually doing the fights. This is in the line of SE's "please tell the summoners to leave their avatars out" weapons.
Even if the latent is only activated when Ifrit is summoned (I believe it, I know for a fact that the Carby Staff is that way), the +3 STR on this weapon is pretty nice. Maybe not as nice as some things out there, but it's still definately there. Plus, if Summoner is ever modified enough to have summoners actually keep avatars out (SE has said it... at least they acknowledge the problem), this might really start rocking.
Unfortunately, the latent is only active when someone in your party has Ifrit actually summoned. It's the same as all the new avatar weapons and their respective avatars.
Makes sense to me. I mean, it's not like the bow ITSELF is Ifrit (which I'll point out SMNs DO get....duh). I mean, just because of the name of the item happens to correlate to that of an avatar doesn't AUTOMATICALLY mean it SHOULD be useable by a SMN. What about the high level THF Dragon set...Dragoons can't equip that. Maybe Ifrit was widdeling this while he was waiting for you to fight him so he could serve you SMNs. He's gotta do something to pass the time. Might as well make a bow. I know what I'd do with my time....