Coincidentally I just received an email from Kamui on this exact topic. My question was to ask about any specific differences in the standard vs.the black tips. I aksed if I play a Moori III medium my understanding was that I should go to the medium/soft Kamui. This was verified by Kamui. I also asked that since Kamui did not offer a medium/soft black tip, which would play like a MooriIII medium. Their answer was to go with a Kamui black soft tip.
As an aside to this, I have really liked MooriIII's in medium but had a standard Kamui medium tip installed on a 314/2 Predator shaft just to experiment. And the standard Kamui medium did, in fact, play like just about everyone elses hard tip. I also preferred the MooriIII feel compared to the Kamui medium. This also translated to the actual sound. The MooriIII medium has a more muted sound than it's Kamui counterpart. So, while I am still very pleased with my usual MooriIII medium, I'm always looking for an upgrade. As luck would have it, last night I bumped into a player who had just installed a Kamui black soft tip. He had it on an OB-1 shaft, so it wasn't an "apples to apples" comparison, but I really liked the Kamui black soft tip alot better than the original Kamui medium tip...so much so that I've ordered one and will install it on my Predator shaft to see if I prefer it to the MooriIII medium. The Kamui black / soft had none of the almost metallic hit/sound that turned me off with the standard Kamui and it seemed to "grip" the cueball better than anything I've played.... English was effortless, especially on long draw shots. Both the MooriIII medium and the Kamui black soft are great tips. But right now the soft Kamui black may end up being my favorite tip.