Up until this evening I had never even heard of them so after some googling I found some saying a 5-6 degrees C reduction in temps but nothing to back up these claims. I then came across this review of the Intel block tested on a 9900k clocked to 5Ghz and while it was the best performing block it was by less than a degree which is far more believeable. I don't think there will be any big advances in performance until somebody comes up with a radically different design of block. Until then I reckon we are only going to see improvements measured in tenths of a degree. One thing that did come out from that review is that it is the most restrictive block on the list, even more than my Eisblock XPX which is restrictive as hell. My personal thoughts are that it's a fine looking block with a good mounting system and the 10 year warranty is very welcome but it's a lot of money for a fraction of a degree better than the other best performing blocks and I don't think it's worth the money. If I was going to buy a new CPU block right now I would be getting the Watercool Heatkiller IV Pro copper or copper ni which is much cheaper and less than a degree off the Optimus.