The article talks about many of your doubts. Using air cooling, there are two very big costs - it is necessary to move a lot of air through, so the fans use a lot of energy (which also adds more heat). And in order to be as effective as possible, the air is usually air conditioned or chilled, which increases the energy used by another 50% or so.
A liquid coolant is thousands of times more effective at conducting heat away from components, so such as system only needs to move small amounts of liquid. Then, once the liquid is moved to the area where the heat can be transferred out of the system (fins, plates, whatever), the surface area of the heat exchanger can be much larger so again no fans are needed.
In the transformers hanging on poles outside your house, a pure convective system (no pumps) circulates liquid coolant up through the copper coils then down through the fins or tubes on the outside of the transformer, letting the heat itself do the work of circulation.
As you say, server farms are going to be the place where this is most cost-effective, but with the amount of wasted space inside a 'tower' for example (much of which is due to the need to move vast quantities of air around quickly), I think a tower or desktop designed for this, perhaps with fins on the back and/or top, might well be the same overall size as your existing machine. And with the convective flow, you would lose the noise and power loss of the fan(s).
I have occasionally wondered why laptop makers don't either put the CPU/GPU behind the screen, or run a heat pipe from the CPU up through the hinges to a radiator on the back of the screen.