I have a brazilian Di Giorgio acoustic guitar with pau ferro back and sides
I can't tell if the fretboard is brazilian rosewood or pau ferro, cause it's a very dark one, but I think it's pau ferro, cause that's what Di Giorgio uses the most on the cheaper nylon models
but I think I never had a solid guitar with pau ferro board
some brazilian luthiers say there's no audible difference in tone compared to rosewood fretboard, others say it's more dry sounding
it definitely feels more like rosewood than like maple