The most aggressive compounds I have are Meguiar's #83 and Poorboy's SSR2.5. Those two usually do the trick on most cars but I have run into a few cars where those two just dont work with a light cutting pad on a rotary. I know there is also a regular cutting pad but I want to get a more aggressive compound so I have more options. I would like to get something from Menzerna since I have 106ff and 85RD and love those two products. I've been looking at SIP and PG. I hear that SIP gives me about the same amount of cut as the two products I have. Any thoughts?