Setup, a setup is only good for a guide. The most important part in a setup is the accuracy of the setup. By that I mean being able to properly adjust your camber, toe in or out. Eyeballing works, but until you can get it setup perfectly and even (thats the key) on both sides, you will fight the handling of the truck. Yes it will be driveable, but little quirks that you are trying to work out by changing other parts of your setup, may really be symptoms of not being able to fine tune the camber and toe.
We helped out several racers this weekend by adjusting camber and toe on our setup board, all of them came back and said it was incredible how much more stable their trucks felt, truggies and REVOs.
It's funny to put a truck on the board and take a first measurement with a camber guage, you always have to ask what they were aiming for in their adjustments, because one side will be -6 degrees camber and 5 degrees toi while the other side is 1 degree camber and 0 degree toe.
A properly, evenly adjusted truck tracks and turns in or out consistently. When you are setup right and feel the consistency lap after lap, you can litterally feel when something gets out of line on the track.