10-20 range is a good target range for the season end (for busy, working people).Yes there is a big difference in the comfort factor with 3 compared to 6; then with 10 -12 you can get to be more like Greg. Tough love!!
Below it becomes too risky.
Above it becomes too laborious.
10-20 range enables you to take calculated risks, try new things, butcher few bees while trying new things ..... and still sleep mostly well at night.
It also enables to run the Mel D's, chemical-free management model (which I largely do).
And still make enough bee products overall, while running smallish units.