JoomlaWatch works just fine. Easy to install and ready in minutes. Publish a small module and component immediately start to display statistic in realtime. I just use it in back end but front module looks and works just fine too.
Working excellent with easy install and fantastic documentation. Highly customizable, from appearance to content. Tested in FF 3.5.3 IE8 and Chrome.
The speed is too fast in chrome, though it scroling nice in other 2 browsers.