I like the Water Wetter quite a bit. Definitely keeps temps down and I think it helps with the corrosion prevention too since it aids in the contact between the coolant and the metal.

Of course, I just spotted seepage on my radiator tank to header seam this week, but having it last 316,000 miles does speak to something.

2002 X5 3.0 315,800 miles
2014 428i 24,600 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

1970 Firebird - Under restoration