My 390 used to puke all the time. Now it may have been overfilled but I always add WW now and puking has stopped. Now 'cooler' is a relative term .
Its probably all in my mind but hey whats a couple bucks and not hurt anything?
I run pure distilled water with water wetter (no coolant). It does seem to work, and it is alot nicer to clean up when changing intakes,radiators, hoses, ect.. I do not live in a climate that has freezing temps though...
I'm running Water Wetter and distilled water in my cooling system and the car seems a lot more tolerant of those nasty sitting and idling situations after being run hard on the highway. It never pukes now and the temperature stays much lower. If you mix this stuff with antifreeze it will pretty much compromise it's effects. Then you get the 5* results cited above. I'd gone through all the other cooling remedies including flex fan, three row radiator, shroud, block flush, etc. The car would run cooler at highway speeds but would get very hot in traffic. The Water Wetter made the difference (that and losing the flex fan).