Steve- thanks for the link, I had a chance to read through the manufacturer's rep's replies. It seemed like they didnt really do any testing of it though (or atleast didnt state that they tested it), and seemed that their conclusions were drawn from their own experiences. I shall try it one day when I have a bit of time, and a very sharp contrasty neg to do it with as I dont have any test pattern negatives.
Drew has a good point with the film, which brings up an interesting question. If you were to use a film with a totally clear base, maybe a lithographic arts film, and were to print emulsion side down, the image would not be as sharp as emulsion side up, with only a tiny difference of the height that the image was exposed at. Unless the totally clear base would effect the light path? But we use glass neg carriers that light has to travel though as well. or maybe I have had too long of a day. lol