Very cool. By the way, this is generally called "mappa" (= "Populus nigra burl"). I devote a separate page to it on my site because it is so cool.
I've never had a solid piece, just veneer, so if you end up with any small cutoffs you can part with I'd love to get them.
I've never worked with it, so can't give you any advice there, but based on the veneer I have, I'd sure agree it seems very soft.