It's a toss up to me, if you already have coilovers. Do you want less unsprung weight on each corner (RPF 1) or 20mm more tire (949). I'd say if you're boosted, go with more meat to help control the torque. If you're N/A, go with less weight because torque isn't as much an issue. If you don't drive the snot out of it though, stay with the RPF 1 and a sticky tire.