Hello,
I also just purchased one of these. I live In connecticut and the lowes here had two. My brother has the 7424 and the 7336SP looks identical. I looked for write ups and the difference is the counter weight (which i believe someone already stated). It allows you to use the larger hook and loop pads with it. I did notice that my brothers does not spin as much with those. This one should i guess. I also got mine for $69 it was onb clearance. I guess no one is buyying them. or at least most Lowes buyers haev no idea how good they are. the decieving part is that is says sander big on the box. You don't relize its a polisher until you read the back and see it comes with the pad. My brothers 7424 is listed as a polisher and he paid $150 for it.