Arbitrator sucks dick, flat out. It can't hold enough drones to last in a fight if you're against anybody that knows what they're doing. There's not enough grid to fit a tank and nos. The Curse and Pilgrim recons on the other hand are amazing.
Er... ECM bonus? (I guess you mean tracking disruptor bonus)True for solo pvp. As for small gang pvp, the ecm bonus is quite handy.