Hard to say what to do to it! I'd ride it and see what you don't like, then make some changes. I have an 08 vector LTX GT, first year for vector in the delta box 2 chassis, 2006 was the first year for the apex in db2 chassis.
All I did to mine was add wider skis, anti-wear pads ( not necessary if your track is fully clipped ), easiest way to get rid of the dartiness is to adjust some transfer in the rear suspension.
Ride it and enjoy!
My vector has been much more rider friendly than my Nytro! But now that I have my Nytro set up the way unlike it I can't see myself riding anything else.