That would be
this thread here, with the post in question by SuperFreak.
At no time did the post mention that the ambient temperatures were constant, and this directly affects the resultant water temperatures.
Sorry for the rant, but I really wanted to squash the myth that more efficient water-blocks lead to (noticably) higher water temperatures. This is a statement that Steve Lynch made at [H]ardOCP when explaining/defending his waterblock roundup, and it's false and needs to be addressed before it becomes one of those "pseudo-facts".
That, and I must admit that I'm a little sensitive about it. Part of the problem with designing a block like the White Water is that it does a lot of things different to what people commonly accepted as "good", so it's always been a bit of an uphill battle to educate just how and why it works, and the side-effects of using it, and cutting through a lot of (sometimes quite strong) negativity along the way.
Maybe I'm just tired and grumpy. Time to go to bed.