Shiny New Shit Syndrome is a serious disorder, which usually breaks out into an epidemic every time something new is released.

Sure, testing might be shinier than stable, but are you prepared to be continually updating your system? Things that worked today will break tomorrow. Configuration file formats will change and you'll have to fold your changes in yet again. Testing is a moving target and if you'd rather work with your computer than working on your computer, you might not want that.