Is .find() faster than basic descendant selecting method?

Question

Slide 30 in Paul Irish\'s blog mentioned:

$(\'#container\').find(\'div.robotarm\') is faster than $(\'#container div.robotarm\')

Is

Answer 1

This is only correct when searching by ID.

But when we search by tag name it returns different results in modern browsers where $('div').find('p') is slower than $('div p') because the latter uses querySelector().