Typically, SEO concepts are very logical. You want your pages to be easy to read, you want your title tags descriptive (bookmarks, etc), you want to make sure users and bots can discover your pages and you want to make sure the pages load fast. But you'd think that Google would tweak their mobile ranking algorithms to factor in page speed more so than desktop.
Most mobile connections are much slower than desktop connections. Although that is changing with LTE. But for the most part, you'd expect mobile users to want to get their content faster than desktop users.
But in a recent Google video from Google's Matt Cutts, they said "it is not that in mobile, we apply that [page speed ranking factor] any more or less than desktop search."
Here is the video:
Again, I'd thought they would tweak that up a bit for mobile search ranking.
They do so for sites that are not mobile friendly.
Forum discussion at Google+.