It has a lot of firepower, and decent armor, especially with a CAU6+ mounted.
I have a CAU6 on mine, and I've gotten into a fight with multiple fighters and they had a hard time making a scratch, and I think I killed one of them, or came close to it... Was with Type 2 Turrets though, with 4's, it would've been better.
Also keep shields in mind. The advanced transport shield is hard to crack, but takes forever to regen. The civilian transport shield on the other hand has the fastest rebuild time in the game, 6 seconds only, where every other shield takes 12. You can more effectively fight bombers with a civi shield, it will rebuild and regenerate too fast for them to be able to snac it off, meaning they will have to get into bomber gun range and strip the shield with normal fire, where your turrets can hurt them more easily.