Digital BW, The Print

I'm very at home with the UT2 inks. It does the job I'm looking for 
in both glossy and matt prints. I'm now looking into purchasing a CFS 
so i can save on ink purchases. After researching the pre-filled CFS 
systms from MIS, I see that they don't pre-fill with photo black ink. 
Why is that? Doesn't the Photo Black flow as well through the tubing 
as well as the Ebony?

This will mean I will have to shell out an additional $33.50 for the  
extra parts as well as continue to buy Photo Black carts as they run 
out. Is this really saving that much money over carts?

Terry Lyons
www.tlphoto.net