You must first understand what is the purpose of the Progress Line.
As summarized from Primavera’s contents menu itself, a Progress Line enables you to view at a single glance the progress of activities against scheduled criteria.
It can be used;
* As a variance line — the progress line depicts variance between the planned and actual start / finish dates.
* As a progress point line — the progress line depicts either the remaining duration of an activity or the percent that has been completed.
In other words, it is a kind of highlighter without the highlighting facility in that it only places a marking line on the time scale side, using streaks going left / right of data date instead of color coding (Oracle should really come up with an added feature of highlighting activities on the left with different colors when using the Progress Line … it will serve the same purpose in a much better way).
That being said, whichever percent complete type you use has in fact no bearing on the Progress Line options … You choose what you want to see … what you are interested in !
Sometimes you will want to see one criteria, another at other times.