Tweaktown published a review of the Nexus XiR-3500 Copper Edition CPU Cooler.

Quote from the review: "Recently I took the Nexus XiR-2300 for a spin and found it to be a very good CPU cooler. Actually, it was the second best we have tested thus far. Today we are going to take the sibling of the XiR-2300 for a spin, the XiR-3500; an all copper cooler that uses the same design.
Between testing the two Nexus coolers I wanted to find Nexus’ secret; how they were getting the performance out of the XiR Series with such a conventional design. After a little digging I found the secret, a technology called SkiveTek, and it is exclusive to Nexus."
Read the full test on Tweaktown.