Imagine being the last turret on the edge of a deep space. You are the colonies first line of defense and no one is coming to save you. While technically not a starfighter, it takes out it's fair share of them. Limited short range boosters keep it out of the line of fire and allow for basic mobility, but this platform is made to outgun, not outrun.
So playing around with an old concept of mine and ended with this - www.flickr.com/photos/53458657@N04/5619170527/ , more of an idea then a polished build, but it's all I got time for so I'll have to "wow" you with my cut and paste editing skills. Maybe a bit of black fantasy in the mix.
Okay, I got to sci-fi nerd-out for a minute... Cool concept but shouldn't they be posted as an inner defense? - Say around a planet, or even system? I'm assuming they're manned? If so, they shouldn't be. What you've built here looks like a perfect remote-controlled defense system. I've had a similar idea (that I hope to build soon) of the whole 'out-gunning, not-running' concept where it would be a Planet Defender ship with only enough thrusters to maneuver and not run (which I think I'll make out of this guy: http://www.mocpages.com/moc.php/258966). These little guys would get taken out all too easy I'm thinking. At any rate I really enjoy your creativity and sci-fi mind. Great build, keep at it! - Matt