I can't comment on MGMATs method, but I can say that Kaplan agrees that notes are an essential part of our strategy as well.

Remember, just because you went back to the text of an RC doesn't mean the notes weren't useful. Did you have to re-scan the entire passage looking for the detail you needed to research? Probably not, because even though your notes didn't have the answer, the included the location of the answer--and by skipping straight to the relevant paragraph and avoiding that frantic search of the whole text, you've already made up the time it took you to scribble down a summary.