Digital BW, The Print

Hello all,

I have a general question. I'm new to digital BW. I'm getting a
Canoscan 4000 in a few 
days and I'm just doing this for a hobby. My question is that I have
an Epson Photo 
750 and a Espon 760. I'm leaning towards using the 750 for all of my
color printing 
and dedicating the 760 for my BW work. Would using the 750 as the
dedicated BW 
printer using the replacement ink produce that much better prints
becuase of the 6 
ink resevore? I have been doing some research and haven't seen much
on the 
difference between 4 ink BW vs 6 ink BW. Does anyone know which would
be better?