Originally Posted by
kbarch
As for dismissing the altitude data that one may collect based on an uncertainty of its accuracy, that's just sour grapes. Power junkies collect notoriously incomplete, inaccurate data, too, but that doesn't stop them from watching their watts. The point is to come to an understanding of what may be more or less hilly, not to determine whether one has actually climbed some equivalent of Mt. Everest (or can actually power an electric toaster).
Power meters are accurate to within a few percent. Elevation, on the other hand varies significantly depending on the device used to measure it. I've done rides where my Garmin reports 2000m vs over 3000 reported by someone's iPhone on an identical route.
Regardless of how you measure it, elevation is a poor proxy for the difficulty of a ride. I think the scale Machka's scale is as good as any.