I was pondering this same question, I originally had a Mayhem Pro, Hated it, way too twitchy and loose in the back end. reced it for one points series locally (and won it BTW) but never got it to stay planted, tried every combo in the book.
So after the RC X-Games began my quest for a better buggy. SP2 or X1cr Pro... ?????
well parts werent an issue for me localy (Jammin) but i did find a Sponsoed Kyosho driver that was willing to help me with my setup, So I made the switch to the big "K". And YES "amainhobbys" is my friend.
just put it together and got one day of break in on the car and now there is snow on the ground, and she sits till next week when im in So Cal for 2 weeks. the SP2 with a B7 and Collari pipe will be throwin dirt.
I guess i can sum all this up by saying, i went for the ride i could get the best advise on setup for. If guys are racing at your track all day with X1's then you might want to go that way, Vice versa if its K-cars etc.