BZZZZT!
Where do you see it all day long? The brown stuff story was a GM factory fill problem.
What do you see with green coolant and leaking intake gaskets? Or do they only put leaking gaskets in engines using extended life coolants?
What happens when you don't change green every two years ?! Try this experiment- put new green coolant in a coffee ***, heat it up and watch the flakes form. This is what you are pumping around.
Taxi fleet testing proved that water pump failures during the warranty period went to essentially zero with ELC because the additive system isn't abrasive like green coolant is.
Heavy duty fleets love extended life coolants.
Why do you think it is a placebo? Car companies have been relying on many forms of extended life coolants for years - you think they are going to risk failures?
ELC is better for heat transfer. The green coolant puts down a layer of additive on every metal component it touches so it is essentially used up after a few days. Then you rely on the stuff sticking there. The reason you have to replace it every two years is because it flakes off, leaving the metal unprotected. ELC additive stays in solution until corrosion is imminent and then passivates the site. The majority of metal stays clean without a heat transfer barrier.