It was definately me. My assertation that Lcomings etc. like being around 75% comes from experience of a/c that have been looked after and flown properly and from people far more experienced than me, both engineers and pilots.
As an ex-engineer with too many hours sat watching a dyno, when an engine is designed the are usually optimised for the power setting they will spend most of their life at. This is especially precient with an engine as crude as the average light a/c engine. Since the introduction of fuel injection, electronic ignition and especially variable valve timing we can now have engines that are good across the rev range, but if you remeber back to a car/bike engines of a few years ago, then they were always better at one thing than another i.e great top end, no pull low down. How much technology do we have in lycomings?
If you read the charts in most POH's, then you can get the correct power settings without needing a fuel flow meter.
If you have a sufficiently powerful a/c, TB20 for example, then pulling the power back after T/O isn't an issue. The problem is when it is done in a lower power machine for example a TB10, which doesn't really have much excess power. 500'AGL is about the lowest height I'd recommend for pulling the power back, but I have met people who do it lower. This is normallly followed by a rollicking followed by a discussion about carb icing and engine failures.
Cruise climbing is a very different regime of flight than the initial climb and a lower power setting is obviously sensible.