I'm guessing that the vast majority of people posting in here have no idea what a "mobile" design is versus a "responsive" design. A mobile design is an ENTIRELY different design that is a one-size-fits-all site that is triggered when a user hits your site via a mobile device. These often have domains that redirect like m.site.com instead of the desktop site.com.
Responsive designs redesign the ENTIRE site so that it has different CSS rules and other HTML outputs that get delivered based on browser-based device detection (far more accurate). This changes the site NOT based on a yes/no mobile/not rule, but based on screen resolution and size. So it looks different on a phablet, vs a small phone, vs a large tablet, vs whatever.
Which is better? That should be obvious. The question is how many of you can pull off a responsive redesign of your sites...