Here is some pre info. on a test just recently finished. The Gemini Blocks appears ahead of a few top contenders.
GEMINI BLOCKS
I called and talked to Peter this morning. I can tell you he has a brain. His idea's come from a technical background and not from a trail & error method that some use.
Reviews:
Quoted From John Hill @ Overclockers.com
"Pump: Eheim 1048 (158gph)
Radiator: D.D. Heater core (low pressure drop)
Tubing: 3/8" ID Silicon
Vertical lift: 4 inches (insignificant)
All Water Blocks 3/8" ID straight hose barbs
All Water blocks inlet water temperature 25C
CPU: Athlon XP1600 12.5x145 (1822 Mhz) @ 2.05Vcore = 112.5Watts
Gemini High Flow Core Temperature=41C Efficiency=.14c/w (consistent)
Gemini Low Flow Core Temperature=41C Efficiency=.14c/w (consistent)
Swiftech MCW-462u Core Temperture=43C Efficiency=.16c/w (consistent)
D.D. Maze-2 Core Temperature=45C Efficiency=.17c/w (best of three tries)
I was totally surprised by the results, especially the Danger Den Maze-2. I was equally surprised that the Gemini Low Flow block did as well as the High Flow block, considering the slower flow rate that the 1/4" channel causes. (120GPH vs 158GPH)"