I can easily get 420 DPS on MNK on last boss Sastascha and 390 on DRG and they aren't even my main. I have someone in the guild, probably one of the best Dragoons on the servers who went Ninja because Dragoon is no longer reliable. Monk does more DPS T10, 11 and 12, I don't know about 13. So does Ninja. Just to give you some perspective. On his Dragoon he would end up with 390-400 DPS on T10 (BiS) after being a DRG the whole game. On his Ninja he had like 410 DPS after playing Ninja a week with a i110 weapon. On MNK he would probably get around 440-450 DPS.
The thing that makes DRG such an unattractive class to play is the TP that is drained like a pool of water being found by a man dying of thirst in the desert. The class is so unforgiving as well and sometimes it's just not exactly in your controll. If your Heavy Thrust is not hit from the flank, it's a HUGE DPS loss whether you reapply it or just don't. MNK and NIN are more forgiving.
I do believe that Dragoons need a small buff.