I always see a ten deg drop when I run straight water with RMI-25 which is a water pump lubricant/surfactant plus some other items that prevent antifreeze precipitates when using in with antifreeze. I have found it to work better than many of the water wetter products.
When one runs straight water, one must run some lubricant package to prevent corrosion and maintain water pump life.I run a three pass radiator on one of my cars which keeps the hoses in the factory locations but which requires a high flow water pump to overcome the high flow resistance caused by the three pass core so that water velocity is maintained. The three pass is nice because it keeps the hoses in the factory positions whereas the two pass requires some rigging.
You neglected to highlight the comments about fast water flow being a good thing instead of a bad thing as we often hear from those that don't understand that one cannot run the water too fast thru the radiator.
Perhaps the most important thing in the cited article was the mention of propylene glycol and how bad it is in comparison to water or ethylene glycol with regard to temperature. I have seen that first hand in one of my cars.
If you are interested in a more comprehensive write up on cooling systems, I suggest this article
http://mysite.verizon.net/vzezeqah/sitebuildercontent/sitebuilderfiles/coolingsystems.pdffor something shorter, these series of tech tips from Stewart are good
http://www.stewartcomponents.com/tech_tips/Tech_Tips_3.htmBe warned that both dispose of the folk lore about moving the coolant thru the radiator too fast.