From my observation of riding with people who don't measure power, on a long ride when the objective is to simply ride for 4-5 hours at a moderate effort, people riding on feel will generally significantly up the power uphill. Weaker or heavier riders may not have a choice. Furthermore, some seem to take it too easy on the flat (in comparison to what they could do, looking at their uphill power), hills just force their hand.
It’s a reasonable strategy sometimes, too: I do it when trying to beat a time, or on a hilly triathlon, too - up the power uphill (trying to stay within FTP for the most part, not to burn matches which I'm going to need later) and lower it on the flat slightly to something more sustainable over the hours.
Anyway, there is no real way to equate the two short of using power or at least heart rate / RPE, because it is about the effort and it is entirely possible to go on a conservational pace chatting with your mates uphill.