On my SpeedMerchant, when I ran the low roll center, the car had an extreme amount of rear bit.. it was like I could put enough steering into the car, I ran the stiffest center spring, but that made the car a little skittish on any thing but the smoothest tracks.
Now this is for me and my feel. I think for me it took some effieciency away from the car, made it feel like the car was just sucking up the batts. Now this is a very slight feel, but that last .1> or .2 secs makes a big difference.

I am just looking for the right balance, can you guys post your setups on the Rev3, springs ,front end type, castor, camber
and for the CK, and the 12l3
Casey