This does nothing to settle anything on the issue of course, but as a matter of pure anecdote:
I recently auditioned the Paradigm F3 with it's beryllium drivers against the B&W 803D3 (diamond tweeter) in the same room on the same equipment.
For me the high end frequencies of the B&W were much nicer, a more beautiful sense of harmonic richness, distinction and clarity to cymbals and other high frequency elements. The Paradigm sounded somewhat opaque in comparison.
I was surprised as I've never been a big fan of the B&W speakers.