No matter what anyone wants to tell you, the difference between one properly designed profile and another is the area under the lift curve. Take the following example of two profiles being compared and they both have the same lobe lift and the same duration at 0.050. The profile with more duration at 0.100, 0.200, 0.300, and so on would be the better profile. This profile would have more area under the lift curve. Very seldom will you see these higher lift duration figures published unless the cam grinder is very confident in his profiles. The lash setting will also play a part when comparing profiles. A wider lash setting will use up more of the area than a narrow setting. The cam profile and the proper lash setting will tell the whole truth. Remember, I started out by saying properly designed profiles. A profile can be designed with more duration at the higher lifts (more area), but the profile may be too aggressive for the application, and can actually damage the valve train. My approach is to balance more lift area with smoothness and reliability of the valve train.