That's correct. I ordered it direct from the factory with the Hard As Nails coating. I didn't specify it as such in my previous post, because so far as I'm concerned, a high-quality epoxy coating is pretty much equivalent to any other high-quality epoxy coating (i.e. my Carvin LB70F doesn't have the Hard As Nails, but does have an epoxy coating courtesy of HG Thor).
Sorry, no sound clips available at this time.
I haven't heard BB's Hendrix album, so I can't compare tones for you. But I'm sure you must be aware that hard-coated fingerboards tend to offer a little extra sustain, along with some extra transference of the upper midrange & high frequencies, relative to an untreated board. That certainly seems to be the case with this instrument.
However, the one ace-in-the-hole that my Bromberg fretless has to offer is the custom GraphTech Ghost piezoelectric system that I had installed on an aftermarket basis (i.e. post sale). This one is similar to the Ghost that Carvin sells stock, but has a three-way toggle switch to select pickups only, piezo only, or both - along with a separate piezoelectric volume control.
This is my first instrument with a piezoelectric system - but it won't be my last! I love the extra dimension of fullness, presence, depth and organic quality that it adds to the magnetic pickups' output - especially for fretless playing! Yowzah!
MM