We were agreeing largly.....
I have a lot of time in 152's and have found them v ery consistant not just on the personal leaning technique you mention but accross the board. My friends who fly my aircraft occassionally manage the same fuel flow figures as me I think the leaning range and operating range generally on a 152 is pretty narrow so it is easy to get consistant results.
The problem with actually measuring the fuel us on a 152 is that unless you have something like a fuel computer or diligantly measure the fuel used on every flight by checking at the pumps is accuracy in dipping the tanks. 2 people can dip the tanks using the same stick and get different readings due to very minor differences in the position of the stick and the angle they put it into the tank.
I think this is where the majority of the myths come from about fuel consumption!
I reqularily fly to 3.5hrs on single flights, a thing that brings most people out in a cold sweat!
I could not agree more about the people who just fill it up and hoipe for the best. Some of the places mine has been in would not be possible at full fuel!