What I can see from this upgrade of 10.3, is that we don't get 4k Ultra HD image output. Considering the wider colour gamut additions and being able to handle 4k footage. In addition, no improvement to colour correction tools and no Cimema DNG sequence imports. The three features I wanted most.
After the update, it looks like I'am getting much better performance out of my SSD drives while shooting 4k raw. Kingston Hyper X , OCZ Vertex 3. I can even get the Crucial M500 to be recognisable and useable after the format. Of course the Sandisk Extreme Pro was good straight out of the box.