I bought this brush pen and the red one too ,out of curiosity.
I can't say this is the best brush but this may be a great brush for detailing.
Just one thing to mind when using this brush pen on rough surfaces. Mine got a
little blunt after a few strokes on my 300gsm watercolor paper.
Overall it's a good brush for detailing, drawing and general writing.
A tad little to the pricy side for a brush pen.
good brush control on the thickness.
brush nib gets blunt easily over several usage.