Ok, now that I've had a bit of time on the Busa I can compare properly with the ZX14. My Busa now has similar mods to the 06 14 I owned for 3 years, including slip ons, pc, bar risers, dyno tuning, etc. The 14 dyno'd at 169.8bhp and the Busa at 173.5 on the same dyno. This is at sea level in Vancouver, BC. Out of a max of 10 I'll rate the primary aspects:
Motor: ZX14 8, Busa 10 The Busa is a much easier motor to deal with. The 14 comes on with a major rush at about 6k on the tach which makes the bike very difficult to control even at half throttle. The Busa is much more linear and doesn't have this turbo style rush to the same extent as the 14. The also proves out on the dyno charts. Winner, Busa!
Brakes: ZX14 9, Busa 8. The ZX just plainly has better brakes with much better feel than the Busa. The Busa brakes are good, but have a much spongier feel. I actually added Galfer steel lines to the Busa which made a difference, but still not as good as the 14. Advantage ZX14.
Comfort: ZX14 9, Busa 8. The 14 feels bigger which makes it more comfortable on longer runs. The Busa seat pushes you forward and there is also a definate buzz in the bars around 70mph which was not there on the 14. This might be caused by the particular resonance of the yosh r77's vs the Muzzy's I had on the 14 but either way it's there. Winner for comfort is the 14.
Handling: ZX14 7, Busa 9. Definately the Busa wins here. Everything that makes it less comfortable makes it feel lighter, turn in is quicker and the front is much more planted and confidence inspiring than the 14. For twisty highways I can run the Busa at least as fast as my old school GSXR 1100 and Ducati 851. For such a large bike the handling is amazing! Advantage Busa!
Looks: ZX14 8, Busa 10. No doubt about this one. The white Busa turns more heads than any other bike I've owned, and I've owned quite a few. Older people, young kids, car guys, young and old women alike all love this bike. I cannot park for any length of time without people stopping to look and comment. And believe it or not, almost everybody knows what a Hayabusa is and stands for. The fastest bike on the planet! Advantage Busa!
So there you have it. I've tried both and for my type of riding I'm glad I ended up with the Busa! If I was touring I would go back to the 14. But for weekend rides and around town, the Busa tops my list. Total scores: ZX14 41, Hayabusa 45!