Yeah, for sure overclocked systems are more maintenance if you’re setting them up yourself. If you’re buying a pre-overclocked system with a warranty, then it’s just business as usual since the manufacturer did all the leg-work.
I personally don’t rely on water cooling for overclocked systems. IMO a high quality air cooler is the way to go for CG work. Less maintenance, less parts to break, more reliability since everything isn’t relying on the water pump functioning. Just don’t toss the machine around so the large heatsink doesn’t damage the motherboard. That’s honestly the only reason manufacturers avoid heavy duty air cooling because of motherboard damage during shipping. That and they’re all capitalizing on the whole liquid cooling frenzy, and the myth that it’s quieter than air coolers even though they still have fans to cool a radiator on top of a potentially noisy water pump.
The closed-loop water coolers are meant for gaming systems that run hard for hours at a time, not months. Their pump monitoring software often is Windows only and intended for people who are present at their computer, not away while the machine is doing calculations unattended. Sometimes closed-loop can eventually create pin-hole leaks and leak coolant on your graphics card, ruining it.
The more extreme open loop water cooling systems that don’t use fans that require coolant changing typically have better cooling capability than closed-loop, but IMO are not at all suited for CG production work or render farms.
I think closed-loop coolers are perfectly fine for normal systems, overclocked gaming systems, or servers (who’s CPU’s don’t get as hot even under 100% load). I just think there’s too much potential for problems with an overclocked CG production system or rendering computer.
On another side note, I’ve noticed large air coolers cool the CPU better when the case is sitting on its side with the heatsink on top of the motherboard instead of sticking out sideways from it. I’ve seen consistent 3 degrees C less than when the case is upright. I suspect the heatsink’s weight is more evenly distributed on the CPU.

