As far as I can tell it involves a shelf nut, and a particular method of intonating and tuning. For example, the G string (open) is tuned -02 cents and the 12th fret note is tuned +01 cent. Kind of like a "sweetened" intonation and tuning.
Most folks seem to find it more pleasing to their ear, but some complain about the Korg tuner recommened because it isn't that accurate, OR just not accurate enough to get the correct notes needed(+/- 01 cent).
However, this is just me reading - I have no idea.
Since I've never personally heard the BFTS, I would be intersted in hearing what everyone has to say. Also, what kind of costs would be involved in the retro fit? Has anyone had the retro fit?
Thanks to everyone.
Bill.