So I recently got my BTO 27" iMac. i7 (3.4ghz), 680MX, 8 Gigs of RAM. Any kind of Flash being played fullscreen runs extremely badly, I have narrowed it down to software and Flash Player. So I don't want people suggesting that it's my internet when my Macbook Air/Macbook Pro/Self Built PC don't have these issues. I also installed Windows 8 through Bootcamp on this iMac and flash runs perfectly on the Windows OS. This is extremely annoying since now Safari has become unusable for me, and the only Browser capable of somewhat stable playback is Chrome after uninstalling the flash used in everything else. Chrome's native Flash Plugin runs decently, but on a machine this powerful I wouldn't expect anything less than flawless performance and taking advantage of the 27" screen to watch my TV Shows and Films.