We've had some threads previously on this topic, here is the gist of them...
Although the all-copper version of this HSF is way over Intel recommended specs, many people are using it successfully. In fact, I have not heard of problems.
On the other hand it has also been shown that the all-copper and the aluminum-copper hybrid versions provide almost identical cooling.
If you do a search on this forum you will find the links to the related threads with included links to authoritative reviews and benchmarks.
BTW, anyone needing one of these HSFs quickly, or wants to see them in person, they are available at Micro Center brick and mortar stores.