Oh they are different bikes. The Z-H2 is to the H2 what the Z1OOO is to the ZX1O. Geared shorter for more kick, less top speed. Of course, being sans fairing, top speed isnt where the Z lives. Its an urban gorilla, making more torque lower in the R's and more upright position means more comfort, more seat time. The H2 has a lower compression ratio, meaning you can cram more boost (air/fuel) in the chamber making more HP safely. The Z-H2 is already maxed out with 11:8:1 comp, meaning the effective boost PSI that can be applied is already there @200hp. When the brains figure out the ECU there may (should) be more HP to be found, but honestly, I lifted the front shifting into 5th at 100+ and that was with wheelie control on. its fast enough for me, and If I ever think I need more power, I'll turn off the TC. Got 1,200mi so far, and I'm loving it.