I tell ya, that would be a tough call. I am very impressed with Kawi and my 12R, and that new Zx6RR is SWEET. But, I am also familiar with the R1 Ian has. If the R6 has the capability of the R1 with less motor, than MAN would I be swayed that way. Then again, you can't deny that Honda has the best fit and finish in the industry. And based on my history with my RC51 and Ian's old black bird, Honda builds some pretty tough bikes. In the looks department, they all are great IMO. The R6 turns my nut because the headlights are sweet and Blue is my favorite color. The Honda looks good because of its similarities to the GP machine (front fairing and undertail exhaust). The Kawi is all new this year and has some really trick options that come with it (shift light).
I wouldn't base the decision on power if I were you. You will never see a difference on the street. If you lose to a different bike on the street, they were a better rider.... probably applies mostly on the track as well.
In other words, I don't envy you. I would try and find a place that carries all four brands of bikes and try and compare them all at once. Sit on them, put your feet on the pegs, get behind the windshield (if you can), and see which one just plain looks better to you. You want to buy the bik that drives you crazy when you open the door to get it out. It's all about what makes you happy as far as your eyes are concerned, because like I said, on the street the performance of all these bikes are so close, it will never matter.