Since I started racing with my X10 last year and with the X11 this year, I have never broken something serious on my Pred.
Only had some serious diff-problems on the EIR-race, but this got sorted out when I used the new diff-parts, .. and never had the same problem again.
SO you must indeed be unlucky
.
ABout the KevLee-setup: I tried it on a grass track and it was SPOT ON!.
But then, I tried it on the Astroturf-track of Kampenhout (Belgium) and my car was very twitchy too.
So I'm gonna try some stuff to make the car smoother on this high-grip track. (We were running on very old used minipin-tyres and still had plenty of grip).
Also, I had some slipper-problems on the Pred. Didn't seem to get it right ... and then I just did set-up my rear diff tight but ok, loosened the slipper completely .. and tested and stiffened the slipper bit by bit, until it was ok. I had no more problems from there.
I think the track you are talking about is a very bumpy clay track, isn't it?
How is the grip on that track?
Have been there also: loosing faith and thinking about selling all my RC-stuff. I'm rather new in setting up a car and it's not easy.