My opinion: Argosies are very solid ships - enough cargo room to be a great freighter ship and enough weapon space to be an offensive threat - however, its rather steep price, and more importantly its lack of strong shields, makes the Argosy a ship that you should avoid at this point in the game. While having one in your fleet is nice (the ship is much stronger than a light freighter) flying one on your own isn't. I recommend staying with the Clipper until you can afford a better ship than the Argosy.
Computer controled: The computer plays the Argosy - which is always neutral - the same way it plays the Courier. If attacked, the Argosy stays in one place and unloads both its turrets. The turrets can pack quite a wallop to a smaller ship; even the Clipper may have some problems disabling it (without an armor upgrade). Larger ships will find that disabling an Argosy is simple, and that they make a nice addition to a fleet. Argosies are also popular amongst pirates, and a mysterious group of Argosies protected by Defenders has been reported in various systems...
