29ers, Single Speeds, DH, XC, Endurance, Enduro, 650b, each shines (or gets dirty) in a different aspect of Mountain Biking.
There is definitely nothing standard about a Fat Bike. 100mm Bottom brackets, offset forks, 4 to 5 inch tires. Even though technically based on a 26 inch rim diameter(559 ISO), you can't call them a 26 inch tire though, with those super swamper rubbers, they measure more like 29 to 30 inches!
I like most bikes and don't really hate on any type of bikes, even Road bikes and Penny Farthings! The internet is full of "My bike is the best and yours S@#ks". Sort of an, "If you don't ride like I do then you are not where it is at". Now it is great to love the riding you do but don't knock it until you try it, is what I say! I have more of an X+1 philosophy on bikes. The only limits I have are financial and space.
My good friend and the "Terminus of the Buck" at Cycle Craft in New Jersey has a fleet of Salsa Mukluks and was generous enough to hook me and a teammate up for a trip to the New York/Vermont boarder. The guys used my birthday as the excuse. To get a feel for the fatties we rode the small town park of Pine Hill. Three of us brought our 29ers. Our Fat bike guy only rides Fat bikes.
I had to be careful not to whack trees with the wider handle bars (I am Really old school in the HB width department). The wider bars help fight the extra turning friction, off center brake pull and greater gyroscopic effect of the bigger wheels. Two of us were Fat virgins and were getting more pedal strikes than usual, even though the bottom bracket height was really not that low. The pedals just needed an wider swath, due to that 100mm bottom bracket width. You do have to adjust your lines, you know, 4 inches just won't fit between the same rocks that 2 inch tires do. This is just the same learning curve I went through picking lines way back when with 2 inch knobbys anyway. We had a concern of riding the wider Q factor for so many miles all in one weekend, because I had spoken to a rider that said he hurt is back hitting the Fat bike to hard and not getting acclimated a bit more slowly. But neither of us neofats had a hint of a problem.
The most important thing was to get the tire pressure dialed in to your weight and riding style. For my nearly 200 pounds 8 psi rear and 7 psi front worked well. After that, learning just how much you can rock crawl with all that traction was really an eye opener. It is pretty amazing! They definitely did not seem slow either. We really flew through some sections.
Us neofats originally were going to ride our 29ers some, you know in case we hated the Fat bikes, but we soon changed our tune and stayed fat for the rest of the long weekend. We took on Green mountain in Vermont the next day and Seneca Springs in New York the day after(ended in the rain). All three destinations had very different terrain, from tight twisty fast, to big climbs and fast switch back descents to dry, then wet rock crawling.
As someone that lamented the headset standard changing and all the new bottom bracket configuration, I am really glad that we are not still riding 30 pound 26 inch rigid bikes with a 3 by 6 drive trains, 28/28 low gear and cantilever brakes! A fat bike is definitely on my X+1 list!