Lately I was very disappointed with Maxthon and start looking somewhere else. YouTube was a real mess. Now with this Beta 188.8.131.520 You Tube is running like never before. I get rid of all extension. Clean installation. NO any tweak. No weird user agent. Set on ultra mode. Videos with HTML5 play smoothly or Flash.
This browser version is extremely fast. Now the issue is why I am really happy with this version on XP and others user have some problem.
I place snap from You tube HTML5 on my end. Before was NOT all green check mark. Was some "not available" but I do not remember which one...