Flash is much less efficient than other video formats on all platforms, not just OS X. My netbook (when it's running XP) can handle most 720p video well enough,

Flash is much less efficient than other video formats on all platforms, not just OS X. My netbook (when it's running XP) can handle most 720p video well enough, but has trouble with flash videos that take up less than half of that area. It's just worse on OS X (and Linux, too).