I've used MicroPlane's rasp-like hand tools for shaping such as cabriole legs and other freeform furniture parts. I've also used their drums that you can chuck in a drill press. I've found them far better than coarse sandpaper for shaping wood. Now the've come out with discs to fit your ROS, Rockler sells them. I ordered a demo pack of 3 different "grits" and will be trying them out real soon. I'll report back on what I find. The Purpose of this post is to get any feedback on how (or how not) to use them. Is there anything I should do or not do; test or not test, etc?
It seems to me when one has some serious imperfections to take out of the surface of a board these could be a blessing.