I had heard about this plugin before, but only recently did I decided to try it for myself. Blocking flash never seemed all that important to me, just as I’ve never used AdBlock, but that’s mostly because I understand that PEOPLE NEED TO MAKE MONEY FOR THE INTERNET TO WORK… sorry about that…
So, the reason I tried ClickToFlash is because it does something pretty awesome to YouTube videos: it plays them as quicktime videos. This means you get higher quality video, and they load just as fast (or faster).