rh @ ebonite did an experiment a looong time ago, utilizing the v2. testers were given two nearly identical test balls, the only difference being the use of not very visible black mica in one of the balls.
when using identical surface preparation, adding "pearl" to the solid cover, all other things being equal, reduced length and added overall hook. the actual results and CATS data was published in their "quarterly" pro shop rag.
just because you cannot visually see "pearl", does not mean that it is not there!
so i have since thought of covers as...
"soild", no particulate/pearl additive = smoother, controllable breakpoint
"hybrid", low particulate/pearl additive = give it a little "kick"
"pearlized" = duh, here it comes