Mark I've had a couple ZX and a couple I's. However, the reel comparison is my good buddy and tournanet partner has a 08 zx 250, and I have an 09 21 I. We both agree the I-class rides a tad nicer. The I class feels heavier and alittle more lethargic than the ZX, but top speeds are very close. Also the I class tends to float more level in the water than the ZX. The seats are a better fit fore me than the ZX and I enjoy the overall amenities. However, the ZX is not far behind, it to is an impresive rigg.