i just did this today, going 2/2 on it.
75 nin/war, 75 mnk/nin, 71 rng/nin, 75 rdm/whm, 75 rdm/blm, 75 blm/rdm
our first run was a mess. while rdm/blm slept and managed the brd, we killed war pretty easily. lasted just a little longer than a light SC with MB. but then the brd just was really strong. it double attacks and attacks faster than my 75 nin can utsusemi with haste. there is a degree of luck involved, but it has pretty good accuracy and when it does hit, it hits for 300+ normal. then we had a string of deaths due to attempts to sleep/kite and raise everyone. eventually we got everyone up with enough HP/MP to finish it off, at around 26.5 minutes (just short of the 30 min limit).
run #2 went much much smoother. we decided to save TP for the brd. in doing so, the war used body slam once. (jumps way in the air and drops). it 1-hit our 75 blm who was standing near the dragon for over 1100 dmg. utsusemi absorbed the damage for the rest of us. at which point we used SC and tried to just kill it as soon as possible. after we got blm raised, we all went after the brd. instead of fighting it in typical straight tanking style. i kited it while mnk and rng got TP. when they got enough TP, i stopped moving to straight tank while they pulled off the SC with MB. then we continued kiting it until it finally died.
no big money drops, but destroyers did drop for my monk on 2nd run, which made me very happy. it was the main reason we did the fight in the first place.
here are some notes that you may find useful:
1) as noted by others, killing one dragon makes second much stronger. on first run, our mnk/nin thought this was real easy, after the war went down, but changed his mind when he saw the brd (he's 75 nin too, so he knows that it attacks fast).
2) Chaos Blade is the curse move with dmg. both dragons use it. tank must use holy water. there's not enough time to cast cursna then cure. The effect of the curse becomes stronger with each successive usage. at first i lost maybe 50% HP, but then it became 60, then 70, then 80% HP loss.
3) Voidsong is an AoE dispel. only saw brd use it. it removes all food and buffs. not really worth it to reapply food in my opinion.
4) it's easier to kite the bard than the war. the bard stops to cast songs. either buffs on itself (minne/minuet 4, uncanny etude, march) or some offensive one like elegy or requiem. this song time gives you a few moments to gain seperation, which is time to cure or recast utsusemi. if you kite a war, it only attacks you, doesn't really stop. meaning you're extremely dependent on bind/gravity sticking. the brd became more sleep/gravity resistant with time and i have a feeling the same would be true of the war if it were killed second.