I'm not sure what you're insinuating that I don't "get"?. If you possibly think that you can read PAR by eyeballing it, you're wrong. If you think you can go by others readings and settings, you're wrong.this guy gets it
If you have mainly LPS and Softies, sure you can get away with guessing as they show clear signs of having too much light or too little.
If you have a 100% Acropora reef, then you absolutely need to know what your PAR is.