I think the important question here, is what's your intended use for the bike? What kind of trails do you ride? What kind of conditions do you plan to ride in?
When I lived in IL, I've seen a few Surly Fat bikes one the trails. Mainly, they were used when trail conditions are soft, sandy or slightly wet. The tires will float better and get better grip while not tearing up the trail if ridden responsibly. Here in TX I've only seen them in bike shops. I personally don't see the benefit here, as the trails are tight and dry vast majority of the time. Few people ride on the beach and once I saw tracks from one of these bikes on the beach.
TLDR: if you ride on the beach or trails that involve a lot of deep sand, shale or other very loose soil - get the Surly. Otherwise, there are other, better options, depending on how and where you ride.