This is because your truck was previously rolling too much and going beyond the ideal contact patch available with your camber gain curve (i.e. camber rod length or other factors). You previously gained too much positive camber and broke free. Adding more roll to that situation only makes it happen sooner. Removing roll keeps the car more stable. On my T4.1 truck, I also found that playing with the rear limiters really helped as well as limiters put a hard limit on total roll, where as roll center affects everywhere. That way you can tune a little more at low speed with roll centers and high speed with shock travel, progression, or sway bars in 4wd cars.

So... here's where we get into trouble. "Mid corner" can mean a variety of different things. For the front of the car, "mid corner" lasts a long time—basically everything after initial turn in when the car starts changing direction until you are powering out and the rear has squatted. For the rear, "mid corner" is a crude way of describing a long transition that is different in every corner depending on the corner style. In pretty much every corner, your front end rolls over and you turn the front wheels—most of that time is mid corner. In the rear, depending on the corner, you may or may not be on or off power through the corner, on brake, or a whole host of other things.

Generally speaking, for the rear, if you are in a corner, and you let off, and the rear wants to slide out or rotate, a lower roll center that provides more roll will keep traction longer in that situation. If you let off, and the traction gets better, or you grab throttle, and the traction gets worse, the car was rolling over to far and you want less roll, either by way of a higher roll center, stiffer sway bar, stiffer springs, or less shock travel. That is not to say that there are not other applicable changes that could cause all of that such as poor weight placement, spring selection, bad ride height, etc.

For the front, if you are hard in a corner, and it pushes on corner entry, but then as you slow down it starts grabbing a lot more steering—more than you would expect from just slowing down, then the front roll center being raised may help. A low front roll center tends to be less responsive but have a lot more steering at low speed (because it rolls well at low speed), where as a high front roll center will make the car eager to change direction, but will stop steering as much at low speed. A really high front roll center will make the car far more likely to punish you on poor jump landings because the front "has no give" much like a stiff spring. A lower roll center in the front makes a car more plush in general, although it is not always faster by any means.

Try to err on slightly too low of a roll center in front and too high of one in the rear if you're hunting. That way, at worst, your car will be a plush push wagon that rotates in corners but doesn't wash out when you grab the throttle hard -- it can be "wheeled" or driven hard, but it may not be the fastest setup, but it will feel very comfortable. Then start tweaking from there to find your comfort zone... perhaps lowering the rear RC for more in field grip at the expense of high speed corner exit stability, and perhaps raising the front RC for more responsiveness at the expense of low speed steering (good if you plan on straight hitting corners harder and you want it to steer instead of pushing while it waits for you to slow down).

Wayne