If he's rejuvinated (and I think he would be, playing here), I'd rather have 'Sheed to back up the center spot. Dice could play the 5 a little bit, but he's more of a classic PF, 'Sheeds addition height and bulk seems to help make him a little better defender down low. Either would help A LOT, and I really hope we end up with one of them. Dice would probably be a little pricier, and Detroit's going to want to bring him back if at all possible ('Sheed's not returning).
But, I agree; upside to Sheed is likely a little cheaper and maybe a bit better at backing up the 5, upside to Dice is more professional and maybe a little bit better player at this point.