I've long been a fan of the Krait II for AX combat work, particularly since modified guardian plasma chargers became a thing. I never really got the hang of the Chieftan and always found myself wanting for more firepower to help offset my deficit of piloting skill and talent. But the Krait's turn rate has always been a bummer.
On a whim, I decided to give the Challenger a go. If you are someone like me who enjoys the firepower of the Krait, but needs a little more armor and lots more maneuverability, I strongly recommend you try a build like this one…specially in planetary AXCZs. If you're willing to give up an Optional 6 slot, you can plugin a C5 weapons stabilizer and get massive dps. If you prefer the C3, this is still a blast to fly and fight with.
Note: Ignore the power issues being caused by the 5A power plant. The actual unit I'm using in-game is some pre-engineered thing from a long forgotten CG. A nicely engineered 6A will get you the power you need, no worries.