On my B-20, buildup on the bottom (outside) of the blade is seldom an issue unless it is getting very dull - which I try to avoid. It has also been noticed when milling logs with a lot of stress. My buildup starts on the inside (top) of the blade as it is trapped between the blade and the drive wheel. Keeping the dust deflector intact and very close to the blade helps a lot but some woods, usually pine, make a real mess.
I still haven't found a lube that will handle pine reliably. It seems like, for most hardwoods, anything will work but pine is a PITA. Someone highly recommended cotton picker spindle cleaner (this is Kansas, good luck finding that) and the next one I will try is the 3:1 water/diesel mix with a shot of Cascade.
As far as blades, I have tried Simonds, WM, TK, Lenox, Kasco, and a pack of "test" blades from a confidential manufacturer. It seemed that the pitch sticking may have been worse on blued steel but not conclusive - I do avoid pine so my data base is limited. If it is any indication, the last box I ordered were Kasco; fast delivery, great production, and very reasonable price.