Buffering is as far as I know a feature of your browser with html5 video. I'm using youtube with html5 enabled (https://www.youtube.com/html5). And it shows the buffering just as it does when using flash. So the capability is there.
Playback is working perfect, but I really hate a couple of things: - Really small (narrow) position slider. Even on fullscreen. - No buffering indicator. - No timer. I hope the player has options for you to tweak those details.