are you buying the car just 'cause you're bored?.....and want a new challenge?.....or are you gonna race both cars together?...if you're gonna race,I'd get the shaft drive K....at least both cars will have the same traits......
if you want to experiment,AND have a fast car,with hopes of selling the tc3,I'd get the 710.....theres a good base of guys to help you on this forum....and I've seen the 710 run..its FAST!!!