I have a Supermax 19-38 drum sander. It is now time to replace the feed belt. There are two options in the manual, 100 grit backed sand paper type and polyurethane type. I have found both on line about the same price. I have also found the same size sandpaper type @ 120 grit cloth backed at about 1/2 the price of the original. Has anyone tried the polyurethane type and is it better? If you have replaced yours, what and where did you get the replacement?