Originally Posted by Greybeard
A racing smallblock Chevy will lose it's smoothness, you'll feel it and hear it as roughness or vibration.
I hear you and don't disagree yet I've seen these comparisons here before and you can not compare these simple, mostly stock Chinese 2 stroke engines to highly modified V8s or Harleys, Hondas or BMW power plants. Predominately the engines on the majority of the bikes built and ridden by the people here are not modified in any way and specifically in terms of compression ratio. They are not "high compression" engines by nature and my guess is that the failures you mention, head gaskets, stud, pistons etc" are a result of improper assembly and maintenance (proper torque values) by the unskilled. Couple that with questionable manufacturing tolerances and you have the results you've mentioned.
Absolutely no arguments with your advice, if, we were all running kick butt mouse motors or blown big blocks on our bikes but we're not. Therefor my original statement stands. Octane rating has little to do with our little toy engines and how they'll perform.