I picked up the competition spec chassis thinking I'd use it for some rubber tire. I had to quit using the 4MM since it made the fit with the Carbon LiPo too tight, and somehow warped the 2.9 chassis terribly. I threw the CSpec on there in a bind, and actually really like it. The car feels a lot less twitchy than it did before. As for the new top deck, I just use it because the front tires wear even when I do, and it gives a lot more room for electronics.
So, do you guys setup your cars so they have all on-power steering? One thing I noticed when watching Brad is that it never looks like he's off-power, only on and maybe neutral. He asked me to drive his car, which was nearly impossible because the thing would take turns at full speed, and I wasn't used to how hard and fast it turned in. I can see how that would be quick, but it would take some getting used to. Is that just a stock thing, since the cars aren't as fast? Mod and 19T cars look like maybe they transfer weight more than stock cars that seem to turn on a dime at full speed and not break traction.