We at RSD came out with a different suspension geometry package a while back. The geometry on the TC6.2 is not quite right. If it were, the team guys would not be changing the parts over to what they are.
The AE mod is a little more complex as you have to re-drill the rear arms to mount a swaybar mount and I believe also to match hinge pin size. They are also using Yokomo rear hub carriers to match up with the TC4 rear arms.
Our conversion is a little more straight forward and more plug and play.
Our geometry (click on the link to the left) mimics the Yokomo's more closely, especially in the front. The results are more predictable handling, better mid corner rotation and more overall bite. Additionally slop is drastically reduced and durability goes way up.
Many people will say "I'm not good enough for it to make a difference". This is not the correct train of though. An easier car to drive will make you a better driver.
The swaybars are changed because they are easier to set up and the feel is more consistent. Due to the threads on the rod holders, the swaybars on the TC6.1/.2 are always cocked to one side. An easy way to mitigate this is to put in one set screw from the top and one from the bottom on the swaybar tube. This makes sure that as the set screw drives into the wire, it spins it in the right direction.