I have worked for a perfromace race shop and have had many issues with the diamond pistons. The top of the pistons above the first ring have come apart. They were abused, but I have had many other pistons live through worse. I am not saying that they are a bad piston, just if I was spending money for a new piston I would buy one I trust. I just would like to know that the piston I have will live through a mistake like fuel pressure falling off and causing some knock. Just like my sig, JE pistons. Got what I paid for.