According to Fazioli's website, the F308 concert grand has a 4th pedal...

It is endowed with a fourth pedal invented by Fazioli. Located to the left of the three traditional pedals, it reduces the hammer-blow distance THUS reducing the volume without modifying the timbre, at the same time facilitating the performance of glissandos, pianissimos, rapid passages and legatos.

This sounds exactly like the type of "soft" pedal that is commonly found on upright pianos that moves the hammers closer to the strings. I thought the typical upright "soft" pedal was commonly regarded as useless aside from being a practice stand-in for the a real una corda on a grand. So it seems peculiar that such a high end and expensive piano would offer such a feature. Is this really something of interest and use to someone playing on a concert grand?