Sounds like you have some experience with this kind of thing then! Anyone who cites thermodynamic theory with confidence very well should! I'd be really interested in hearing about your studies of localized nucleate boiling - so I'm assuming you have done direct measurement of cylinder head / exhaust bridge temperature or perhaps delta BHP @ temperature to come to the conclusion that the effect is negligible? For my money, I'll try the Evans NGP-R - avoiding local boiling and being able to run with effectively a 0 pressure system can't be a BAD thing....
That said, I woudln't mind if I could lower the water temp a bit, so any work you guys do on an air / oil system will be watched with great interest I'm sure!
The work we did was really related to reducing the temperature on the exhaust bridge to control knock (pre-ignition you might call it). With running boosted through a 34mm restrictor, any slight increase in engine combustion efficicieny is really significant to the overall engine performance (as you have a fixed massflow of air to burn - if you can burn it a bit more efficiently its all good). For this reason, you want to run with as close to MBT timing (best igntion advance setting) as you can, and ordinarily on an engine like that it would start to knock before you had reached the best ignition advance. Improvements to the cooling around the combustion chamber (getting rid of hotspots) might enable you to run a little bit more advance before knock occurs, so we did LOADS of work on cooling to see if we could make it any better.
The work on alternative coolants was part of this, and as much about finding if we had a problem as anything. All I can say is that there was little or no difference in the temp of the exhaust bridge across a power test regardless of the coolant used really. We measured the bridge temp by drilling a very small hole into the metal in that area from the outside of the head, and then fitting a small thermocouple down the hole, glued in place with special conductive epoxy stuff. Then ran off full speed sweep W.O.T. power tests with a variety of coolants to see if there was any effect... Engine output stayed consistent as did the metal temp. We also ran with varying coolant jacket pressures as part of the same work (as this would effect boiling point), and even at 4Bar there was not much effect so the conclusion was that we didn't have nucliate bioling in the first place.
Of course not all engines are the same, and whats true for one may not be true for the other, and I can't argue with the fact that it would be nice to have decent cooling with no pressure in the system! Nice failsafe if your cap gets lost or something. There is certainly no harm to be had in using something other than water / ethylene glycol mixture.
Good discussion though...