I hate to rain on your parade WolfgangR but since I'm assuming (which is always unwise) you don't have an 06 yet, I'd say your speedo is a bit optimistic. 9000 RPM is about 157 mph give or take a bit depending on tire wear, and that seems to be pretty much it for the bikes here in the states and Canada. To reach 170 you’d have to be turning about 9800 and I don't know about you, but on my box stock 04, I hit the soft limiter at about 9500 and it won't even come close to that in 5th. Admittedly, I'm a big guy at 6'7" and 300lb so I may be pushing a bit more air out of the way but... 170. I don't think so unless you've done a fair amount of modes to the engine or decreased the frontal area a ton.
But what I will say is that she will hit 150 pretty quickly. But I doubt if the 06's higher gear ratio will increase the top speed at all. In fact I'd be surprised if the top end wasn't a tad lower all other things being equal. That being said, I still think a slightly higher ratio will result in an even smoother ride at normal cruising speeds and probably better fuel economy. And because of the abundance of torque, the acceleration shouldn't be effected much. You'll just hold the lower gears a little longer.