I don't have much use for one. I have a small Ryobi combo 4X36 belt with 6" disk sander. All I use the disc portion for is grinding scarf joints on lams and sharpening pencils. This will actually be the next piece of equipment I upgrade when I can afford a 6X89 Jet
As far as the 12" HF disc sander, my dad has one that he uses the bejesus out of. He's a gunsmith and uses it to rough shape recoil pads to fit the buttstock of a rifle or shotgun. The one he had, a Pleistocene era Delta as I recall, finally crapped out. He bought the HF as a temporary substitute, but ended up keeping it.