When I commissioned James Goodall to build me my Grand Concert, I asked him about "sinker" redwood for the top; I was living on the North California Coast on a 6 acre parcel of the huge beings (!) and wanted to have a redwood topped guitar...
James' feeling is that with sinker, there is a lot of variation in the tone, from one piece to the next, probably due to different mineral content; he works with what he calls "Master Grade Redwood" instead... feeling that he has a better idea of the tone from the more consistent pieces of that source.