The OpenCL benchmark (LuxMark) result was the most surprising. We did not expect the 680MX to run almost four times as fast as the 675MX. Why is this important? If you are running apps such as Motion, Final Cut Pro, and Photoshop that use OpenCL accelerated effects, then this is a key metric.
The caveat is that the 675MX was running 10.8.3 beta with newer nVidia drivers.