Nice post
There are very few instances where the effort required to attain perfection is justified by the impact - exceptions are probably precision engineering (think O-seals on space shuttles) and brain surgery.
I wrote on here before - as my old PhD supervisor used to say "better 92% right and in than 100% right and never submitted"
20% of effort giving 80% of results is the same as 1% of effort giving 50% of results by the way