Looks like you left out the 7th Gen... If I could only have one, that would be it! Power of a toro-charged 800, and everyday reliability. Does not feel it's weight, and with LSL bars you can really row that thing through the corners! More comfy than the others too...and can still haul the beans fully loaded with a passenger. Way better brakes, easy exhaust valve adjustments, never a chain to clean/adjust/replace, and parts still available!
It's biggest downfall is the looks, and what people think of the weight, and range. They aren't really an issue in the real world, as opposed to what the numbers look like on paper.