Have installed about a dozen of the Black Pearls including on my own league cue(4 months ago). Installs pretty nice and only seems to mushroom right after its first put on. Go out and smack 10 games with it and reshape. Should not have anymore problems with mushrooming. I put two of them on friends cues free of charge to get some feedback on how they shoot. One is a 6 (Triangle tip) that shoots aggressive, hard and powers the cb around the table. The other is a 7 (Morri soft tip) that shoots light as a feather, all natural leaves, only occasional extreme english. They both love them. The six has asked my to put them on all his cues, he is kind of a cue whore like me. The 7 wants one again next time. I personally love mine and I'm gonna do some more experiments to compare it to the Wizard soft which I also love. I just put three more on last night.
Now on to the Karomi brown. I bought 5 to try out at the same time as the black pearls. They shoot well similar to a Wizard soft or Morri, HOWEVER they have to be the worst tip to install I have ever used. Two of the five partially de-laminated during installation and had to be cut off. Once they were on though they seem to shoot well and mushroom less than the black pearl.