Last year, weighing the merits of heatpipes, I bought three of them for the stock-clocked machines within the extended family.
Even so, I had tested the PIPE101 with several 92mm fans, up to and including the Vantec Tornado. I obviously backed off using the Tornado because of the noise, but the figures I got for my Northwood P4 system were much, much better than those shown in the German review.
Very quickly, and seeing the XP120 on the horizon with some other cooler options, I picked up a $9 acrylic 120-to-92mm fan adapter at FrozenCPU. I tested several 120x25mm fans. I since switched to an XP120, but only because it had great reviews and "I wanted to see . . . " It also weighs less -- 375 grams (w/o fan) as opposed to something above 525 grams for the PIPE101.
I think the performance of the TT PIPE101 with fan adapter is about the same as the XP120, provided you use a fan that can spin up to a range between 2,600 and 3,100. And such a fan is still going to be less noisy than either a TT UFO 92mm, a TT Blue LED 92mm or a Vantec Tornado 92mm. Much less noisy.
My point? The PIPE101 sits a little closer to the mobo and may show positive improvements with motherboard ducting. But the purely hypothetical advantage isn't enough to avoid the question: "If you can get an XP120, why fool around with the PIPE101, fan adapter, extra weight, and other drawbacks?"
Note the fan speeds in the German review. I have a different threshold of compromise between noise and performance in comparison to some people, but I really think you have to have airflow to make heatpipes more effective. So I don't run my XP120's fan at speeds less than about 2,200, using SpeedFan to spin up to top-end when the CPU temperature rises above the mid-90's Fahrenheit.
They did the same thing in a comparison using the TT FANLESS 103 -- and in that case, testing it without any fans whatsoever. It was "adequate" for keeping the CPU from throttling down in that configuration, but if you could bump the temperature down 10C or 20C by augmenting the cooler with large 120mm fans, what's the point? Heatpipes are heatpipes, airflow is airflow.
By choosing fans without bearing and motor-whine, what does it matter if your computer case exhibits some white-noise on warm days from the air-turbulence, sounding about like an home AC vent?
For the PIPE101 and low noise, you have to be prepared to spend $10 on an adapter and buy a 120mm fan that pushes maybe 2,000. I prefer a wider range of speed, so I look for fans with minimum motor whine and a range that includes 3,100 rpm.