There isn't a significant difference in speed between Orozco and M2. The main difference is that orozco prepares you for transitioning to 3 style, while M2 doesn't. A lot of people typically use M2 edges and Orozco corners until they learn 3 style corners, and then go straight to 3 style edges, skipping Orozco for edges. Since you don't want to learn 3 style yet, I would stick with M2/OZ