LOL... there's way
less in watercooling circles than there is in audiophile
circles. At least I've never heard anyone claim that they got a faster overclock by placing rocks on their case, or by using cryogenically treated SATA cables made of unobtanium.
Thermodynamics and hydrodynamics are a little hard to grasp for many (myself included to a large extent) - but in general, and largely thanks to people like Martin - you don't have to rely on speculation and theory... because someone
has tried just about everything in pursuit of performance.
On topic... if the 90-degree-bends theory is bugging you... try some of the threads arguing about loop order - they can get really entertaining. (Coming from someone that has had their CPU block last
in the loop to great success).