On Thu, 12 Apr 2012 18:07:08 -0400, "Mike Marlow"
You will create some rather deep scratches with coarse grits, and
the entire area that you have to sand in order to blend the repair gets much
larger. 1000 grit will do it just fine and will not take an unrealistic
amount of time. From there - 1500 or 2000 and you're ready to buff up to a
full shine.

It sounds like the potential is there to ruin the surface with coarse
grits, much less so with the finer grits. Only problem is that the
finer grits seem like the sanding is taking longer.