Retrieve width/height of a css3 scaled element

Question

I'm fighting against an oddity (I think) of the offsetWidth property.
this is the scenario:

I've got, let's say, a span tag, in my js, at a certain point I perform a css3 transform to this element, like:

        el.set('styles', {
            'transform':'scale('+scale+', '+scale+')',      /* As things would be in a normal world */
            '-ms-transform':'scale('+scale+', '+scale+')',      /* IE 9 */
            '-moz-transform':'scale('+scale+', '+scale+')',         /* Moz */
            '-webkit-transform':'scale('+scale+', '+scale+')',  /* Safari / Chrome */
            '-o-transform':'scale('+scale+')'       /* Oprah Winfrey */ 
        }); 
        w = el.getWidth();
        console.log('after scaling: ' + w);

at this point the log returns me fuzzy values, like it doesn't know what to say.
any suggestion?

Answer 1

getBoundingClientRect() returns the correct values for me.

jsFiddle.