I recently changed out my coolant with distilled water and coolant in a 50/50 mixture. Included Water Wetter and have noticed about a 10º F drop in temp :D Yes I am happy. I used the turbo flush method where you use a rubber hose and blow out the residual fluid in the system. Worked great. My Stealership couldn't find the drain sealing washers in the cylinder head (damn squids at the parts counter), so I just got a second 6.5mm crush washer like the one that goes in the water pump. Worked great, same washer. The hardest part of the whole job was the plastic R&R. But glad I did it.

Great..I never notice any difference with WW or Engine ice.