I've not heard that, nor experienced it.
Granted, most of our clients use their cars predominantly on the street, occasional track use, but off the top of my head I can think of 5 customers with over 8 years on their engines, all of which are making more than 550whp, and are regularly pushed in DE, 1+ mile drag races, hill climbs, etc. All engines are equipped with conventional upright fans.
You worked with Loren on this, right? He ought to be able to share his experience on this, too.

Mike wrote:
Thank you for responding, it seems like, what comes down to, is the longevity of the motor and reliability as Loren puts it. I took this setup from a good friend of mine, which he known in the Porsche industry by the name of Turbo Mike. Majority of the parts were purchased from him, and he had done the same setup with lot higher boost and compressions.