[TuringTest]

Personally I think the "fluid" responsive design for article snippets is a mistake; but then I hate multi-column feed designs, so that may be just a personal preference.

Apple got it right with the iPhone menu structure, which was inspired by the iPod (maybe they nailed it because it was not card-based). There, columns always maintain the same positional relation (there are menus to the "left" and sub-menus to the "right"), so you can always remember by muscle-memory where a particular item is located relative to the others. Re-flowing similar items breaks those relations.

Responsive pages make sense when the side columns are used for side content (i.e. "aside" tags, headers and footers, navigation...) - there, placing the sub-content above or below the main content to show it on a narrow screen is not a problem, since the moved card was subordinate to the main article anyway.