Flash and Youtube are not exactly the same thing and not apple to apple for comparison. As pointed out, most major sites are changing over to check for Flash 10, even if the content is not 10. Sites that worked and played content no longer work and ask for the newest Flash player. Seems to be enough posts to suggest there may be a problem with (not Youtube) Flash performance since the upgrade, but again- moot, since most sites will soon not work anyways. Well, the ads will still work, of course