Thanks for your input, Roianne. To be clear, we’re not advocating any particular technology as a one-size-fits-all solution. Properly implemented mobile sites (whether separate URL or dynamically served content) should be optimized for tablets, but site owners have to carefully evaluate the reasons people might be using their site on a mobile device, tablet, or desktop computer, and which method would fit their audience best.

Jeff- thanks for your input. It sounds like you’re replying to the second option, dynamic serving, since you mention a site that “dynamically identifies the user agent.” The extra work comes in having to maintain the mobile site (or mobile version, as you refer to it) apart from the desktop site. The mobile site itself doesn’t necessarily require more work than the desktop site; it’s simply the case that you’re maintaining two sites, whereas with responsive design you only have the one.

The first con gives the impression that there are separate search results for mobile site than there are for standard site. Which isn’t the case. You get the same results as desktop, but if you’ve implemented the proper tags on both mobile and desktop versions, the URL just updates for the version you’re on.

Why would the mobile site need extra work?? If your site dynamically identifies the user agent and redirects mobile users to the mobile site, it’s the main site that gets the actual ranking (and all the SEO work).