KK is the best. i have ridden both of them and KK is better because of the big airtime hill instead of hitting the brakes right after a tophat. for me a good intamin launch coaster should have some good and strong airtime. TTD is somewhat boring: Launch, crushing g's, airtime, twist, brake.
KK: Launch, crushing g's, airtime, twist, MORE AIRTIME, brake.
KK rules