My opinion: This upgraded Argosy is weaker than a Confed Frigate, but cheaper. It's not a bad ship if you're able to obtain it by capturing it (not likely), but purchasing it just isn't worth it. While it can hold up better than a Kestrel it can't even carry half the fire power. As usual, sell the Rocket Launcher if one of these falls into your hands. The Destroyer makes a great escort, it's not too hard to capture with a Cruiser, either.
Computer Controled: The Rebel Destroyer flies very similar to the Kestrel. Its two proton turrent shouldn't cause too much trouble in a close range dog fight, and the Destroyer rarely launches its rockets so don't worry too much about them.