the aggressiveness of the lobe must taken to account depending on the engine's application. For instance, a softer, smoother lobe must be used for an endurance application.
This is an interesting spec that up until recently I used to neglect. You may see 2 cams with identical specs. Check the specs at .020 and compare them. If the cam has the same duration at .050 but one has more at .020, that cam has a more aggressive lobe or ramp angle.