It seems to work, but I have no real data to support it. However, what I have seen is two failures in two other Z's in our local club. One failure seemed to be caused from something hitting the cooler and causing a leak. The other seemed to be a workmanship issue that caused a leak on one of the threaded inlets. The second failure was during the first week of use, so it definitely seemed to be workmanship related.
Two failures in our local club alone. If you use the same population analogies that I used in my short shifter review, you can figure where I could take this, but I will not bore you with it again.
Based on the lack of any performance data, I cannot really draw any conclusions on this part, but bear in mind the two failures that I mentioned in the beginning.
As is case with other Stillen products, there are now other alternatives out there. I have also seen people making there own units with off the shelf coolers similar to what Stillen has done with their product.