I’m using a KLIM Cyclone, mainly for elevation, but bere are my two cents:
First of all, it helps. Not with CPU/GPU temps per se, but it takes a lot of heat away from the bottom of the chassis, so the machine is cooler to the touch.
(I’m waiting for my thermal camera to arrive, so I can put numbers on the topic)
Second, if fan noise is a problem, check out This control center made by an user. It’s free and lets you control fans and CPU TDP!