Is the noise of a pc really that bad to go out and spend almost 2k on a case like that? I doubt it.
Well, personally, the silent hum of my machine does get on my nerves sometimes when I'm stressed out or playing a game where hearing counts. But that's not the target for these cases anyway. These things are for like professional offices, laboratories, sound-test chambers, etc.
As for the heat-pipes, the temperature at the far terminator stays cool for a long time. As the gas inside heats, it moves to the cooler end of the tube, where it sits and is dissipatted into the copper sheathing and the heatsink blocks. Nuclear reactors are cooled in a similar way.
True, though, that after time, if the environment isn't cool, the cases do heat up. These are best used if you have a cooled area, or a distributed liquid cooling system.