Really interesting. I do have a hefty loop consisting of a MO-RA420, 2x D5 pumps and a Heatkiller IV Pro.
Would be cool to see if this would be a better performing option compared to the traditional waterblock.
Well yeah. It says it in the article. But you get more surface area for initial heat removal. With more water flowing around the heatsink, you could theoretically remove more heat and remove heat faster.
And since water can absorb more heat at a time than aluminum (fancy little site to help out with the math - koolance.com/cooling101-heat-transfer) before it's temperature will increase, it could theoretically lower the temp of the metal below ambient to allow the xpu to be even cooler.
Yes, water can lower temps below ambient.