Unfortunately I do not know the difference between mine and the commercial units.
I have trawled the net but I can't get even the slightest hint on the internal operation of the commercial units. They keep all their details commercial in confidence.
It maybe that they use cross correlation which seems to be some sort of gold standard.
I will be happy with mine if it compares well with the WMR100.
I run a log of each. Sofar mine is much more accurate at the low speeds where egg cups are poor. At the higher speed there is good agreement.
A wind tunnel would be nice. I no longer have access to such facilities.