I actually just traded Demaryius Thomas for Spiller in my PPR league, and also have Rice. To be honest I think it's a coin flip but I would give the edge to Rice personally. He's a more dominant back when healthy and so involved in the passing game, is the goal line guy, and always just seems to get double digit points in PPR. Spiller is great too but the time share is of concern. Also Jackson has been more effective lately. I would go by whoever your gut tells you because it's a pretty even trade in my opinion.