Yes, more bias equals bigger bumps - to a point. When you are working with fine detail like skin, you can obliterate detail by being to aggressive with the bias. Thats where the filters can help you manage it. The Condensed filter is good for smooth noisy maps down while the Sobel filter helps pull detail out. 

The other adjustment, blur, lets you get away with using maps less than 2K by de-pixelating them a bit. 

There is no perfect setting. adjustments will always have to be made for intensity due to scene lighting. 

It's all smoke and mirrors.