Running 17.5t on my KF2 SE
The medium stiffness front and rear arms are much more resilient to breaking. Included hard compound arms can break easily if you hit them just right. Medium flex lets you get away with a lot more. After tons of abuse the only parts I've broken are wishbones. (local track offers free practice, averaged at least 6 hours of track time per week for 3 months when I got the car)
The shock tower guards do their job very well. A lot of people at my track don't use them but they're worth installing imo. Especially up front, keeps the shocks and tower from grabbing the carpet and after a lot of abuse my tower and shocks look new underneath.
Motor position all the way forward or low grip (one step back) are both very good. Have run both, don't have a favorite, just different. With the car built to box stock setup other than motor in low grip position, it is excellent. I'd recommend to start with that. Great mix of forgiving and aggressive. With the motor all the way forward it can be pretty sensitive to adjustments but pushed harder....but crashed easier
