Digital BW, The Print

I managed to get everything I could out of my Ultrachrome inks and 
finally decided to move to a set of grayscale inks.  I spent this 
evening learning how to use the UT7 inks in my 2200.  After lots of 
cleaning cycles, I finally got a good head check.... I then used the 
curves method with Paul's neutral EAM curve: fantastic, selenium-
looking results.  

I then tried the other curves with pretty poor results.  They had 
poor contrast and looked somewhat posterized.  I then tried the 
slider method as Paul listed and had great results for both warm and 
neutral.  I even managed to get a slightly cool image out that way.  

The question is what might I be doing wrong with the curves?  I'd 
sure like to have the flexibility of the curves method as I'd like to 
have a bit moe control and eventually try to split tone.  My process 
is to open the grayscale in 16 bit, convert to RGB, apply the curves 
and print in Adobe space (also tried colormatch space) and no color 
adjustment.  Any thoughts?