Digital BW, The Print

I just tested a MIS FSN ink set with the Cone driver on Hahnemühle 
Photo Rag 308 gsm. I have previously used the original Piezography 
inks (quite successfully) but I wanted to try something cheaper.
I was not completely satisfied. The results can be seen on 
http://www.kolumbus.fi/martin.glader/fsn.pdf. The density curve is 
very smooth in the highlight area with a visible separation between 0 
and 1 % (!) and also quite nice in the deep shadows. The problem is 
the mid grey area between 65 and 85 %, which also happens to be a 
very critical area in most images. The contrast is rather low between 
60 and 65 % and very high between 75 and 85 %. I'm editing the images 
with a custom dot gain preview curve, which I have adjusted 
correspondingly but it is still a problem. The Dmax on Hahnemühle
PR 
is 1,60 which is lower than with the original Piezo inks (1,64-1,66). 
Any comments to my observations?
My next test will probably be with the UT inks and the Roark workflow.
Martin Glader