One thing I would like to mention, too, is that, when I have a loop, where I'd prefer low-flow, i.e. run the pumps in silent mode, I like to add a few 90-deg bends, as they act as turbulators, breaking up the laminar flow normally associated with low-flow loops - and note, I am not referring here to low flow due to excessively restricting waterblocks, rather to conditions where you have a relative free-flowing loop.

In these instances, having a couple 90-deg fittings, normally gives me fractions of improvements in water-temp....