Note that in that case you still need the<noscript>part to be in your web page.
Advantages:This method appears to be quite bulletproof. It works fine even if web cache server supplies same page to all the browsers because browser will request different stylesheet. One could say that this method makes the user's browser do the job for your the web server.
Disadvantages:The only problem we encountered is when user saves your web page locally and then opens it in another browser not naving an internet access. In this case browser won't be able to open needed stylesheet file and will render your web page using default settings.