roller chain instead of screws or rack?

Hi, I have built several small router tables out of both wood and
metal with varying degrees of success. I used lead screws and
anti-backlash nuts on all of them. I am now building a 5'x10' plasma
cutter. At first I thought rack and pinion was the best option, but
then while recently visiting a sign shop for supplies, I noticed a
large CNC router in the back. I asked to have a closer look and was
surprised to see a #35 roller chain drive. There are 34 frame steppers
driving the chain through a 3.5:1 reduction. Since the gantry only
goes back and forth, the chain did not make an entire loop, but
instead, half the chain was replaced with aircraft cable. At the far
end of the table, the cable loops around a simple pulley, which is
tensioned with a large spring, getting rid of any backlash. The table
has been in service for 12 years and the owner is very happy with it.
This system seems to be much simpler and cheaper than rack and pinion
and allows for greater flexibility regarding gear reduction.

Has anyone used chain drive before? Are there any drawbacks to a
roller chain drive system?
Thanks