QTR-Quadtone RIP

First off.....be kind.....I am fairly new at B&W digital printing

I am trying out QTR and, so far, I am finding out that I can 
definately get better BW prints from UC inks (Epson2200) as compared 
to other methods I've tried.  I suspect that I am not getting 
everything I can out it, though.  In fact, I almost gave up on it 
using it "out of the box" with the stock curves for Epson Enhanced 
Matte. Then, I found that if I adjusted the Ink Limit to -2 and 
gamma to -4 in QTRgui I could get reasonable prints.  I did this 
through trial and error on a test print.  It seems like there must 
be a better calibration method and it sure looks like the 
calibration mode handles that, but I can't figure out how to do it 
(and I'm a reasonably smart guy.....or so I thought!).  I tried to 
look through the archives, but I did not have much luck.

Second question:  will I get much better results with MIS or Piezo 
inks?  I've tried the MIS inks in the past and had clogging problems 
and I was never happy with my prints (w/o QTR).

Thanks -- Mark Fisher