I'd like to but i don't know how. I tested this in a complex application environment. We did some profiling sessions where we ask ourselfs which parts of the application are most time consuming.

We have some live resizing parts which use jquery ui resize where we modified the callbacks to work with the flexBox model. However we needed to do a lot of calls to the .css() function. And while profiling the application (in any major browser) you can see that retrieving elem.offsetWidth is a very very time consuming operation because the browser needs to calculate it in constrast to retrieving and testing the display property.

Retrieving offsetWidth took up to 400ms depending on the element being resized and depending on how many elements are involved. Retriebing the display property AND testing it was displayed in the profilers with "0ms".

So i can only tell that we're definetly seeing a significant performance improvement but it's hard for me to prove since i'm not allowed to share any code form that application.