What lists have you run with the Defender?
My favorite Defender-centric lists are these 3 (I really enjoy using Vessery).
Echo (Veteran Instincts, Weapons Engineer, Fire Control System, Advanced Cloaking Device)
Vessery (Opportunist, Heavy Laser Cannon, Engine Upgrade, Assault Missile)
Two Ship Tango:
Jendon (HLC, FCS, Weapons Engineer, St 321)
Vessery (Opportunist, HLC, Engine Upgrade, Assault Missile)
Delta (Engine Upgrade, HLC) x 2
Backstabber (Targeting Computer)
Plus an assortment of mini-swarms, Firesprays, and Interceptors. All of the Defenders play well, I have just developed a particular attachment to combining Vessery with a Weapons Engineer. The ship with the Engineer uses one TL on their own target, and the second one goes on the ship Vessery is about to hit. Good times.
The most lopsided game I have had so far was Vessery+Jendon vs a 3 Dagger (HLC, FCS) list. Jendon firing 4 dice TL/Focus, then Vessery firing 4 or 5 dice TL/Focus. It took exactly 3 turns of shooting to bring all 3 down. When they came into range, one of the B-Wings used its Barrel Roll to get out from behind a rock for next turns maneuvering. Jendon fired at him with TL and focus, and hung 4 damage on. Then Vessery used the Assault Missile with Opportunist (he had been handed his TL by Jendon several turns ago), and because of the mechanics of Vessery's ability, those 5 dice had TL and focus as well. Boom, dead B-Wing and the other 2 took 1. The next 2 turns were Jendon and Vessery firing with 4 dice either TL or TL+focus at the two B-Wings, and they went away in short order. Good times.
I don't want to overstate the Defenders abilities, it is certainly not unbeatable especially if you are still getting used to its unusual dial. But yes, I would agree that it is the best fighter in the game, and has a price tag to match it. The ship works, without breaking the game, which makes me happy.