In Snow Leopard, Flash was a very slow, laggy experience. Scrolling in a website with Flash loaded resulted in heavy lag or Safari freezing. However, now in Lion, Flash is incredibly fast! There is zero lag while scrolling in a Flash heavy webpage, and Youtube videos load instantly. I'm not exaggerating, they load as soon as the page itself loads, sometimes before the other web elements load. Impressive. I am using Flash 10.3 Beta for 10.7.