I have raced the last 6 races with the Hetrick Pipe and love it. I have no experience with the CT but looking at the pics that Gabe posted they look to be the same exact pipes. What's inside of them is unknown. I love the quality of the Hetrick Pipe. I don't know what the price is on the CT but the Hetrick is very good for a whole system compared to Sparks. I am really happy with Hetrick customer service. They are just really nice people to deal with. If you have any questions just ask.
Ray
1999 400EX-99 Hetrick Racing 416 motor, FCR 39mm Carb, Hetrick Racing full exhaust, 2000 pc'd and gusseted frame, 450R shocks w/ GTT springs, Elka converted rear stock shock w/ GTT XC link, Hiper wheels w/ Holeshot XCT's, Graydon Nerfs and steering stabilizer, PRM Bumper and full skids, Wave rear rotor, TrailTech Computer, Sidewinder Ti-Moly Chain and Sprockets, Cycra handguards, +1 Steering stem and Protaper bars
07 DRR 70 Built by Hetrick Racing, w/Elka Shocks