My opinion: The Corvette is an excellent ship at a great price. It can hold plenty of weapons and buying a couple mass expansions won't hurt the cargo room at all. Once again I recommend doing away with the bulky Rocket Launcher and stocking up on missles. Buying five proton guns and two proton turrets will prove to be deadly to the enemy. Buy a layer of Durasteel armor and a layer of Armaplast. If you have room left over buy another javelin pod, it'll double your output of the rockets. As an escort the Corvette is quite a treat; stronger than a Rapier and much more durable. They're not too hard to capture with a Kestrel/Frigate/Destroyer/Cruiser, either.
Computer controled: One of the more powerful ships you'll come accross, the Corvette is only used by pirates and local militia. Avoid conflict with them unless you have a Kestrel or better. A fully equipped Kestrel can make short work out of a Corvette; but once again, avoid close contact with Corvettes, they're armed with heavy rockets!