I totally agree w/ Diseasel300. I published my MS Thesis in the Int J of Heat & Mass Transfer and have engineer'ed in many industries (not automotive), so not a total idiot, but nobody is paying for my thoughts so value as any free comment.

As mentioned, several aspects to over-heating. If you "boil over" (i.e. exceed pressure of the radiator cap spring), you will lose coolant and then gets much worse. 70% water/ethylene glycol has the highest boiling point of the mixture, but you can get much higher w/ pure glycol (~350 F). Evans Waterless is that plus a mixture of propylene glycol, and the later is sold as Sierra Coolant (up to 5% water, but can boil that off). Racers run pure water (w/ cooling additives), but perhaps more for track rules since glycol leaks are slippery.

If your T-stat is controlling (80 - 90 C, i.e. not wide open), then the specific heat of the coolant doesn't matter since "good enough". Of course, the heat rejection also depends on the flow-rate. Heat transfer involves several variables, which proves confusing to those who said, "I'll never need this" in high school math and science. But doesn't stop them from spouting their confused "common sense" on websites. One long passed around among hot-rodders is that a restriction disk in coolant path helps by "giving time for the coolant to cool off in the radiator, if it passes thru too fast it doesn't have time". Not kidding. You can find a web article where an engineer at Robertshaw traced this silly concept to 1930-40's cars w/ a weak radiator cap spring which would burp coolant with a beefed up water pump that gave more flow pressure, thus the restrictor reduced line pressure. But, can't kill that myth.

Of course, anti-corrosion is usually more important. In the 1990's, I couldn't convince relatives in Indonesia to use anti-freeze. They ran pure water and their radiators clogged w/ rust. At least, they were smart enough to use condensate from the home AC. No auto parts carried it and all said, "never freezes here". I noticed they use it now and no old vehicles are seen on the road.

I run Evans in 6 of my 7 vehicles, and both 300D's, since I value anti-corrosion most. I also retrofit w/ silicone hose when I can. Even new cars have cooling limits. I understand one place manufacturers test new designs is on the I-5 south grade going to LA (i.e. Grapevine) on a hot summer day (meaning >110 F to you easterners). My 300D's hit 104 C there on a hot day, so "good enough" and without corrosion should stay that way.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans