"a real-world camera will almost always show more noise"
Never thought I would see this outside of maxwell fan forum :D
Not sure what you mean... Give me an example so I can check my wording to be compliant with what you expected.
What I'm saying is that if you go out with your camera and shoot stuff with the conditions mostly given (no additional light setup) you end up with noise in the image no matter what, and even if you take the high-end gear + a light setup, a photograph will never be noise free. But that's not what we're discussing here.
The problem with the examples from Vray is - again, for me, not sure how they'd say it on another forum - that you end up with a completely noise-free wall next to a noisy object for example. It just doesn't look natural. Adaptivity should do its work on areas that take longer to sample to achieve a level of noise matching the rest of the image. It's more a balancing than completely removing any noise.
I agree though that, after all, it's probably a personal preference and the need for entirely noise-free images will depend on what the desired outcome is.