I think you could get good results out of this if you use a macro lens or enlarging lens as suggested - better than the flat bed scanner. It would also be a lot quicker than a scanner once you have got it all set up, with flash for constant lighting.
I have a Nikon Coolscan V but it is very slow, and I feel I have never learned to get the best out of it. Part of the problem is that my slides are not completely flat in their mounts -- the DOF on the scanner is very shallow so that I cannot get the corners in focus. It does a good job on film strips, though.
Maybe I should look out for one of these Ps6 jobs myself...