I have been running B20 in all things diesel around here (97 Dodge, 04 Dodge, 3 Tractors and a Kubota RTV). No problems whatsoever. In fact, you may have a slight improvement in mileage as pure bio has a little more energy than petro. The engines also sound a little smoother.
You MUST winterize (if the supplier doesn't) if you have low winter temps, as the gel point of pure bio is around freezing depending on what it is made from, and I think typical gel points for B20 are in the neighborhood of 0 F.