Why did you choose the F800GS over the F800S or ST?
Its kind of a similar question.
I think you would be happier with a Rubi. Its a more cost effective route to go unless you are some kind of heavy duty wheeler who is planning on changing out all the stock components.
Stock it comes with 4.10 gears w, dana 44's, front & rear lockers, elec swaybar disconnect, heavy duty transfer case, and a warranty.
All that shit adds up big time. Especially if you plan on paying someone to install it all.
BTW mine pulls my SuperEnduro & XR400 on a small trailer just fine.