I see that your in NY. DO NOT SWITCH TO B100. Pour some into a jar, seal and place in your freezer. See how it reacts. Does it freeze? Does it jell? Swirl it around has it gotten thicker? Running a B20 ratio may be fine. (8 gals Diesel/2 Gal Bio)
Once you know how it will behave in cold weather I would up the ratio, but being up north I wouldn't switch right over.
Biodiesel is a good lubricant, helps with lubricity in ULSD. Bio is also a good solvent. It will dissolve any residues in your tank that is why they tell you to keep an eye on your fuel filters. I'm all for Biodiesel I try to run it in my 92 300D when every I can. You just have to take a few precautions. Or at least be aware of them.
Interesting reading...
http://www.biodiesel.org/pdf_files/Changes_in_Diesel_Fuel.pdf