Well, Legato 3.1 installed, I took the voltages down to 13v so overall current drain not too far off before, initial impressions are therefore based upon pairing it with the old Placid BP. Unfortunalely also by Stax headphone amp doesn't like the common mode DC bias on it's balanced input, so I have it hooked up SE now.
v3.1 certainly seems to have more 'grunt' than then v2, more immediacy and 'up front' presentation. So far with only an hour or so on it, I would say is a bit harsher souding than the v2, but more dynamic and digs out detail better. I'll put some more time on it tomorrow and let it burn in before final judgement.
Regards