I know this could stimulate much debate but with the advancement in chain technology and metallurgy, I wonder if shaft drive offers much of an advantage anymore. Cleaning/lubing modern, sealed, O and X ring chains seems to be not an onerous task. There are still those that think chains need to be cleaned every few hundred miles, yet many chains go thousands between cleaning and then it is more of a cosmetic thing. One of the mods over on the Stromotrooper forum routinely gets 40-50K+ miles out of his chains (he keeps pretty good records and has over 300k miles of experience with the big Vstrom. He doesn't clean them but does lube them often.
Personally, I wouldn't let the lack of a shaft drive keep me from considering any bike.
Now, if you mix oil and tires into the equation..........