I have no trouble running it in 64bit mode, but I DO have issues with full screen mode, which apparently only works on main screen, and won't scale properly in the browser window so it's off center. It also doesn't allow for very low quality connections, such as I like to use when I'm using my 3G card on my MBP. It does appear to provide a slightly improved picture over the application, but the desktop app allows for more customization of the stream.
Overall, I find this provides only moderate benefit over the old application, and only if you have a very fast connection.