Are data attribute css selectors faster than class selectors?

Question

A few months ago this article pointed out that classes could actually be avoided all together from website development.

My question is, how efficient are the data s

Answer 1

I wouldn't call it conclusive, but it does appear class selectors are faster... I just put this together for a quickie test.

http://jsperf.com/data-selector-performance

EDIT:

Based on Vlad's and my jsperf tests... if performance is a concern (especially IE)... classes are still the way to go