I'm running B-20  for the 2nd year now and have had no problems in the combine or tractors.

I will preface this by saying that I have pretty good filtration on all my storage tanks and change all fuel filters on machines every time I annually change oil.

My combine has multi fuel filters starting with a fine mesh screen in the sediment bowl, and additional filter on top of the tank (listed as an export model filter in the parts book) another small plastic mesh filter on the back side of the injection pump and 2 filters in series.

I've had to change fuel suppliers since a co-op bought out my independent supplier and service and pricing immediately went down the tubes. New supplier said that the refinery is adding a additive package to soydiesel and they will add something too as temps get colder. It's been a great product here so I hope it is not taking the rap for some bad  diesel fuel in an attempt to discredit alternate fuels.