Fuji X100S vs Nikon D800 focusing

Lately been using my X100S and really enjoy its black and white pictures as well as it’s light weight for a travel camera but I sure miss the view of a 85mm lens and focusing speed of a Professional body. If you were doing general photography I would strongly advise on a micro four thirds camera with a fast lens such as a olympus m.zuiko 17mm f/1.8