I've tried ChromeCast with my Ubuntu. It works perfectly. Even screen mirroring, while friends on OS X had problems with it. Just check for Chrome extension.
My Chromecast doesn't work too great due to my router, but I'm hopeful that it will once they release the feature that removes the need for the Chromecast and casting device to be on the same network.
It DOES NOT however not work on bad wifis and networks. Verify you your router configuration (there's tons of routers that block multicast over Wifi by default which doesn't work well with Chromecast) and wifi network quality.
It doesn't work well on good WiFi either. My work WiFi requires a username and password, so it isn't possible. My home WiFi isolates all clients. Any hotel WiFi I ever saw requires a click through agreement.