I have one of those floating around here somewhere -- but the simple test strip (using about 1/3 sheet of paper) tells me so much information that I have never felt the need to use one of the projection print scales. I suppose it is just a matter of what one is use to doing. A carefully placed test strip gives me info on exposure, contrast (over-all and local) and how much burning and dodging will be needed. But then I also always make a straight work print, too.