It is not that I don't like 6 speeds....the majority of people do harm to their motors by shifting into 6th gear at too low of a RPM.
So now that we NEED that 6 speed gear box we have to change the gearing to 3.36 to make the drivetrain a workable combination.
So what are we trying to accomplish.....better fuel mileage...you get on average 3 mpg better mileage by changing to a 6 speed, how many miles does one have to ride to have the change pay for itself....
longer motor life.....which most of us will change bikes before we wear out the motor.....
so IMHO leave well enough alone and ride your scoot till you get a new one 
Brian - Brian - Brian, I think you are missing what some of us are looking for.
As you know, I am looking to lower the overall gearing on my bike, I feel as though it is geared too high, even for my light butt. And add a passenger and I think it just isn't enough "git up 'n' go". And I think a little lower gearing will make it just about perfect riding through the hills.
So lower the overall ratio and overcome the increased RPMS with the addition of #6.
Increase the R's 400 with the gearing, drop it back down with the 6'r.
As for better fuel mileage - that's like trying to justify the diesel in my truck but getting 2-3 miles a gallon more - and that is an almost $8K option.