I completed this in three tries in DF with my lame i113 WAR (DRG queue was ridiculous ). It's funky new content, and while it does indeed take a run to get used to it there's no reason whatsoever a DF party with decent players can't do it if you communicate.

Also, don't put DPSers on cannons - it's a waste. You need one tank to tank and one healer to heal him, so naturally the second tank and healer should be on cannon duty. I put a melee on the boss fulltime to help damage quite a bit and the bard was given Dragonkiller duty while our two BLMs AoEd the living shit out of everything that was nibbling on me under the boss. Wasn't that bad but a really fun learning experience. I may have been lucky with the people I got in DF though, dunno.