This isn't entirely the fault of the brushes. Both of those things are also an attribute of the paper, which I'm aware of, and try to incorporate into the techniques I use with this paper. However, the combination seems to be too much of same thing. So I'm going back to my Silver Black Velvet brushes for my '52 Weeks of Watercolor Paper' series.
I'm using a Stillman and Birn 9x12 Beta series wirebound sketchbook for all my '52 Weeks of Watercolor Paintings 2017'.
The brushes used were Princeton Snap brushes 3/4 inch flat, and Sizes 4 & 20 Round. The pigments used were Sennelier Primary Yellow, Indian Yellow, Sennelier Orange, Sap Green and Daniel Smith Lunar Blue.