The XJ series boasted increased shield capacity, better maneuverability, and higher sublight acceleration. The starfighter's weapons carried an increased charge and better targeting computers, making the craft a formidable enemy of the foes of the New Republic. Additionally, a third proton torpedo launcher was added to up the fighter's payload to 9 torpedoes total.
The XJ model of Incom's incredibly successful X-wing series was one of the more recent versions of the venerable starfighter. When the war against the Yuuzhan Vong started, these models were rarely seen outside of the New Jedi Order and elite Star Destroyer and battlecruiser squadrons.