Mobile switch more than is mobile is not mobile
People on tablets prefer to browse the Desktop version.

From this page: https://developers.google.com/webmasters/smartphone-sites/tablets:


  If your website has different pages to serve desktop and smartphone
  users and does not have tablet-specific pages, in our experience
  tablet users usually expect to see your desktop site rather than the
  site's smartphone pages.


Mobile switch does not work with caching on.

So I'm using the php code from this site:  http://detectmobilebrowsers.com/

Also see : https://stackoverflow.com/questions/11381673/javascript-solution-to-detect-mobile-browser.

So if you want more control, you need to write your own module giving the flexibility you need.