my .02 cents on havok , i run a 13.5 w/ gtb ss in my truck and a 13.5 w/ xbr in my buggy , i can not tell any difference between the two , ok maybe i suck , naaa , just a mid pack kinda guy out ta have fun club racing , im getting the havok system because of the throtle expo setting that my spektrum radio doesnt have and there cheap , ray