As far as I know the functionality difference is just the flange for the toolchanger. They both contact the same on the taper and use the same drawbar tension and both locate only on the taper. A difference is that the notch for the drive dogs are different and if the spindle dogs are set up correctly this one can only fit in the spindle in one orientation, but the Haas spindle can take both in either orientation. I think the alleged superiority of one over the other is self-delusion.
An open mind is a virtue...so long as all the common sense has not leaked out.