stepper to servo transition

Greetings all,

I am new to this group (and Yahoo in general), and hope my query
falls within the group's subject. I am writing in hopes that your
collective wisdom can help guide a decision I am trying to make.

Some background-- I have been building my own NC machines since
1990, although you might find that term a bit of a stretch when
applied to some of my stuff. All the gory details can be found on
my site: "The Art of Motion Control" -- http://www.taomc.com In a
nut shell, my obsession with DIY CNC has evolved from creating my
own shop tools (plasma cutting, routing, milling, engraving)
to "live performance" machines-- NC machines as kinetic sculptures.
And, as another branch, to educational projects and materials.
The "art machines" section of my site covers the former; "teaching
machines" the latter.

I am now working on a large scale installation of a four-axis device
I call "Ribbon Dancer." All my work thus far has relied upon open-
loop steppers. I have extensive experience with them, and have
written software that allows me to fluidly move 3-axis systems along
paths I create in AutoCAD, sending a step/direction stream out the
PC's printer port. For this large and very public piece, I think a
closed loop system will be necessary-- which has prompted me to
consider using servos (the budget is ample). I have begun to get my
feet wet in this regard, and now realize that this is a deep
subject. I was drawn to this group because of the direct experience
that many of you have in bridging the gap between steppers and
servos. I have read the FAQ, and searched the archives-- I hope I
did not miss a section which directly addresses this.

I am documenting the Ribbon Dancer project at:
http://www.taomc.com/art_machines/ribbondancer.htm

My specific question is this: Am I "hobbling" myself if I use step
and direction control for a servo system? After playing with servos
for the past month (see the scrapbook link) I need no convincing of
their performance advantage. But, now I need to create a bridge to
my "choreography." Thanks for any / all input.

Bruce Shapiro
Artist-in-residence
Science Museum of Minnesota