Digital BW, The Print

I had been printing just grayscale film images, but I am now fooling 
around with desaturated RGB files from  a 6.1 mp dslr.

1.) In reading about different workflows, I see the 
term "partitioned" workflows being used.  What does this term mean?  

2.) Is there a quality difference in a print from a (dslr) grayscale 
file vs a (dslr) desaturated RGB file?

3.)  Same question as #2, but what if the source is scanned color 
negative?

Thanks, Val