great brush pen overview! i'm a bit of a brush pen obessive as well and a good bit of my sketchblog (link below) is devoted to trying out various brush pens, but i'll have to admit that you really went above and beyond.
if i had one tidbit to add, it would be this: pentel brush pen + moleskine notebook = big win. the smooth paper in the moleskine notebooks is a perfect fit for the pentel (and other brush pens as well). it's like butter, baby!