Following the installation, and after checing that everything was running smoothly, I first took note of the noise level (subjectively, of course|) - then used an audiometer from 1 meter away. Sealed, the chassis is close to being inaudible, with only a slight blowing sound from the front-fan making it through.
The cooling is still excellent, though not necessarily as great as it was on the Silent Base 800, and surely not on par to the results we got on Fractal Design's Define R5, another noise-isolating tower. The first graph below is for temperature - listing Idle & load temps for the CPU, and MOBO temps in Load.
With the BIOS set at Normal speed, and the middle-selection in the fan-controller, the noise level were still below noise-room level. There was a slight sound coming from the case, but nothing noticeable, and certainly nothing that would draw attention or cause frustration during a particularly