I heard those gelid fans have greater static pressure than the 1850rpm gentle typhoons (2.66 mmH20 vs 2.06 mmH20) and both give off a noise level of 26 db.
Gelid data :
GELID Solutions > Products
Gentle Typhoon data :
Static pressure data for gentle typhoons
This surprises me as I had always heard that the GT are some of the very very best. Looks like there's an UV green option that still kicks ass for watercooling.
Edit: Could the GT just possibly be directing the airflow in a better-for-watercooling way? I heard that the GT kick the crap outta silverstone airpenetrators too because they have really directed air flow.