Gotta choose a sanding belt next... but how?

I recalled an article in Fine Woodworking in which they compared the effectiveness of several random orbit sanders using an clever method. They weighed identical boards before and after sanding for an equal amount of time. I figured that this method could be modified for this purpose so off to the shop we go. I started by cutting and then weighing identical sized pieces of plywood. I chose ply because it looks like this is what Accuride used for their track. My thinking is the belt that removes the most wood in the allotted time would be my winner. Good idea? I don't know, but it's all I've got.