Here is a picture of my study in textured view from Bryce 5.5. (inverted in photoshop)

There is 7 radial lights and 2 Spotlights in this scene. 

All the radials have a setting of 100% soft shadows, an intesity of 15 and falloff set to "squared".

Note the close group of radials near the desk. (Thats 4 there)  This is very important as each shadow "edge" cannot be seen.  EG: If i had all the lights spread out evenly, there be shadows all over the place.

I place 1 radial inside the ligth fitting and one above.

For the Spotlights a setting of intesity 5, softness of 21 and squared falloff. These two were placed to illuminate the box on the floor and the sockets on the wall. Again 100% soft shadows.

The key to a quick (45mins) render was the "panels" for walls and floor. This were pictures of textures rather than DTE materials. I lowered the diffusion to 40% on these to help control the overall effect here. This also helps counteract (bigword!) the light from near the lightfitting.

Rendered at 64RPP. Postwork was just a bit of sharpness and glow.

Hope this helps anybody,
Alex,