Datacolor User to User Support Group.

Well I went ahead and picked up the Z3100 and have been playing around
with it for the last week.  I was wondering if anyone on this list has
had pretty extensive experience with it.  I've tried using the
built-in HP printer spectro and built my own profile (Innova Smooth
Cotton) just using the 225 patches.  PFP profile comes out better in
almost every image I've tested.  

My question pertains mainly to Black and White printing.  When using
the PFP icc, do I print in color mode or grayscale mode.  I was
thinking that grayscale would be similar to the Epson ABW and that icc
is not used for this method printing.  Can anyone here advise their
preferred method for using the Z3100 and PFP?  Grayscale mode
supposedly uses four grays to print so I was hoping to take advantage
of this.  Will Color mode also use the four grays?

Any advice or workflow would be appreciated.

Thank you.