I have a surly Wednesday and it's a great quiver killer bike, at least for the type of riding I do, which is rough road foul weather commuting, occasional moderate to nontechnical trail rides, and seldom realized but grandiose touring/ bikepacking aspirations. I've even ridden it a bit on the highways as a roadie and it does a fair job of that (heavy bike= better workout right?). I've been impressed with the 3.8 surly nates as an all rounder tire.
Where I live the roads are pretty poorly maintained, and definitely not designed well for bike commuting, and the weather is awful, lots of snow and ice, so I find the fat tires helpful. Plus I appreciate being able to take the bike on mtb trails, and the fat tires are entirely adequate for the level of gnar that I'm up for shredding. Your situation may vary of course, but if you're willing to sacrifice some speed for additional comfort and versatility then fat bike as only bike could be the way to go.