"Optimize Selectors" guide requires update?

"Optimize Selectors" guide requires update?

  1. // Fast:
  2. $( "#container div.robotarm" );

  4. // Super-fast:
  5. $( "#container" ).find( "div.robotarm" );
The  .find()  approach is faster because the first selection is handled without going through the Sizzle selector engine – ID-only selections are handled using  document.getElementById() , which is extremely fast because it is native to the browser.
JSPerf test: http://jsperf.com/jquery-find-checked-checkbox (see the stats) 

$('#nav-sidebar').find('input:checked') vs $('#nav-sidebar input:checked'):
  • Google Chrome 35: about 91% slower
  • Internet Explorer 11: about 8% slower
  • Firefox 29: about 27% faster
According to browser usage stats http://gs.statcounter.com/#desktop-browser-ww-monthly-201405-201405-bar Google Chrome is the most used browser today. Then goes Internet Explorer and Firefox

So " $('#nav-sidebar input:checked')" is faster to more users and with time the situation will continue to change.

This issue requires testing in different operating systems and browsers with various selectors. Please help testing!