Kodachrome 64 Pro, scanned, has given me some of the best black/white prints I ever made, including those from original b/w films. The skin tones available from the material were fantastic even at its its zenith as a colour medium (of course, others will say that for Ektachrome instead) and that the same holds true for b/w conversion is remarkable.
Apart from the fact that it was a film that lasted frozen forever, it had a massive resistance to latent image failure - you could have it processed at the end of a couple of weeks of shooting and the early shots were as good as the last. Velvia seemed quite good in that respect too, but not a choice, for me, for skin,
I thought it had been stopped a while ago, Kodachrome, with processing only in Switzerland until stocks had run out...
Rob C