QTR-Quadtone RIP

I have been surprised by the quality of the black and white prints I
have gotten from my Epson R1800 with the standard inks and regular ICC
profiles made with Datacolor Sypder3Print. I have gotten the
impression that I can get even better monochrome results with
QuadtoneRIP and downloaded to see what it can do. I used Moab(Legion)
Entrada paper and these settings:
QTR2.6.1
Printing model: QuadR1800
Curve:UC_EEnhMatte-black
Resolution: 2880 dpi
and got a dark, somewhat muddy print (from a 16-bit gray tif). I
realized that I had Photoshop (CS2) set to Dot Gain 20%. I changed it
to Gray Gamma 2.2 and tweaked my image so it looks good on my
(calibrated with Spyder2) monitor. I am reluctant however to print
again before making sure I know what I'm doing - the paper is hard to
get and quite costly where I am.
Are the printing model and curve I'm using correct for the 1800 with
Epson Ultrachrome inks? Am I right in using Gray 2.2? 
I have ordered both Piezography Neutral K7 and MIS Eboni 3MK inks and
will need to know how to use QTR when I get them :)