Dont get one - they clonk into first gear. As if the Hexhead doesn't (or any other bike for that matter).
IMO the new Adv looks styled ugly (like a Hummer) rather than just form following function. It will soon look dated.
OK, all bikes are styled but the GS has (previously) had less styling and more function than most bikes. The 1150 and 1200 have stood the test of time in style terms