Remember back in the day when guys would talk about their engines coming up "on cam"? It seems with all the really good tech info on this thread about cam profile and ignition advance, without knowing it that's what we were talking about back then.
When it all comes together and the engine hits it's "sweet spot", you want that to happen by the time you hit your normal cruising speed. I have a fairly hot solid roller going in, and a 3:31 rear. I chose the .82 TKO trying to keep the engine in it's slightly higher than normal RPM "sweet spot" during cruise.
I know, it's not a highly technical term, but sometimes easier is better.
Sort of the KISS principle.
By the way, just FYI, I got my .82 TKO 600 in two days from Mike Forte. He's got a bunch he keeps in stock, great guy to deal with as well. I was very pleased to work with him.