[kk3]

Someone who understands normal flow and positioning, how elements interact with each other, and minimizes the amount of code for each part of the design will be much more effective than someone who knows all the short cut css hacks.

Also, a bunch of these questions were far more relevant during the IE6 era which is now finally at a decline. I would care that someone knows how to code for IE6, but that requires one question since all IE6 bugs are very well documented, just make sure the person is aware.