I'm extremely happy with the ZEX 10lb. flywheel in my EX. Granted launches are kinda wimpy now, but then again I have no longer have any intention on drag racing with the car anymore. I've found AutoXing so much more fun. But anyways, if you do switch flywheels, you may as well replace the clutch with a STG2 or 3 ACT. I hated the stock clutch from day 1. But, that's just my opinion.