Use of large pitch/lead ball screws

Hello,
I'm after some advice on using a ball screw with a larger pitch.

The optimal ballscrew / leadscrew pitch appears to be 5mm / 0.200".

I've managed to get ballscrews for the shorter axis of a home CNC
machine however finding a good quality ball screw for the long x
axis, with a small pitch, is very difficult. I'm now considering a
ball screw with a pitch of around 20mm. From what I have read you
will loose resolution and not transfer torque to linear motion as
well with the large pitch ball screws. It seems to me, however, that
if you gear down the drive motor sufficiently you can get back to
the resolution of a finer pitch ball screw. In addition the
specifications I've seen for higher pitch ball screws have a
reasonably high load rating.
What issues/disadvantages are there to consider with going for a
larger pitch ball screw?
Thank
Robert