I do not have Valle Negra,to say for sure ,it is the same cultivar.
From what I have seen,Pixies on this site,of Valle Negra,My opinion is,that yes is similar.
However ,The health of the 2 specimen might be different,which will make them produce more or less fruits,and resist more or less to Winter cold,in northern climates.
As for Nero 600 M ,i can confirm it is totally healthy and ,because of it ,it will grow back fast,in the Spring,to make it possible to ripe fruits even after total die back in the Winter.
As Proof,look at ,the plant above:It was ,the third year ,as age and it was planted from beginning in that spot,it died both ,harsh Winter we had in 2014 and 2013,and so you can see the ripe fruits,now,and yes they are late ,much later than ,normal but ,enough early not to be killed by frost before getting ripe.
That is ,good news for north east,and ,for northern gardener that ,are willing to grow in pot,and use the ,method of the buried pot 3 inches down,in a sunny spot.