This is an upgraded, Block-2 derivative of the original AC Orion.  Based around the updated Cobra nose cone, the new model is slightly longer than the previous version.  With basswood wing structures, it is also more rugged as well as better armed. 

The Block-2 version is optimized for engaging and targeting capital ships rather than operate in a mixed strike fighter role, and as such has a brand new fire control system, Astromech droid integration, and uses an ion cannon, laser torpedos and a particle cannon in addition to quad-turbo lasers.