I must admit I am somewhat hesitant to declare a drone-based destroyer to be "instant awesome", particularly for the Amarr one which lacks other DPS.
The reason is this: Against a traditional 7-small-gun-destroyer setup, light drones simply evaporate; against the old-style super-Dramiels, I found that one of the best ways to fight them to a standstill was to shoot down their drones. This could be quickly accomplished with my weapon groups split 4/3, and the 10% hull HP bonus on the Amarr hull may only give that a few seconds longer life. The Arbitrator is a lot more durable in this matter, since those TDs mean you can force a target's tracking down to nothing; the destroyer does not have that, though.
So, I suspect a lot of it will come down to tactics.