Making single frame of JS code to run fast is cool and dandy, but eventually browser will have to make freeze and do reflow+repaint. Eventually it will make profiling harder, think about caching .offsetHeight etc. properties. It does decrease script execution time, but it does not make your app to work faster.
if you do something like
$('a').each(function(k,e){
$(e).append('<span>' ...);
var width = $(e).width()
// do something with the width;
}