I expected that others would have opposing experiences and tried to reflect that in my comment. People are different sizes, flying different class, frequenting different airports, traveling with families or solo, for longer or shorter periods of time, more or less luggage, etc. So of course it won't be universal.

My main point is that all time is not created equal, that it matters WHERE you shave the minutes/hours off, not just what percent of overall travel time is removed. And while we disagree on how to apply this, we seem to agree on that main point.