A little to small is easier to live with the a lot to big. If the Cam is big , you can get away with higher,but don't flip-out. I don't like having to add those little expensive cans of octane booster to my tank. It's a good combo of all the stuff working together. RPM High R's are ok for a well built and maintained RACE Engine.
Today there is so much Good stuff out there .
But for me, MSD is it.