I practice regularly and trade off between two Z2 shafts, each has a Kamui H. In stroke training over the past few months I have spent over 100 hours shooting diagonal, table length draw shots. All I've ever done is rotate the tip in a dime shaper after the occasional miscue (when I drop my shoulder trying to get extra oomph on the ball - body english). There has been absolutely no mushrooming, nor any other deterioration, whatsoever, that I can observe.
I don't understand how anyone could say these tips delaminate, or anything else bad. To me, it's just like when some people say that Predator shafts suck (feel hollow etc.) I just can't understand that!
FWIW, I practice on 9 foot brunswicks, in very good condition, and frequently draw back to the pocket I shot from. No, I don't try to do that every shot, I'm not trying to impress anyone that I am superman - just trying to backup my opinion of Kamui's.
I have my tips installed by a custom cuemaker, who trims them with a razor blade. They trim neatly and easily and, thus, don't heat up. I suspect that if anyone is having delamination problems, they overheated the tip when trimming - that's a No-No with any laminated tip!.
The tips I'm shooting with now were installed about 6 months ago, and still have two thirds of their original thickness. I always use to cut my tip thickness in half, after installation, because I like very hard tips, but these kamuis proved to be so explosive I didn't want to change them. Next time, I'll cut one in half and leave one full thickness, because I suspect the extra thickness adversely affects deflection (JMO).
Sorry for the long windedness, but finally let me say I recently bought 10 more Kamui tips just to be sure they'll be there tommorrow.