Didn't do JTA, but Kraken was INCREDIBLE!! It is a floorless coaster. Not inverted like DD. The floor drops out once you are seated, so your legs swing, but the track in under, not over you. It is a WAY longer ride than Rock N Roller Coaster and has some VERY steep hills. It is very smooth though and easy to take. We got there early and I just got right back on to ride it again. I don't know your son, but I sure loved it.