I use the 3-D feature constantly. In the early years I had mixed results. I would try to put enough light fixtures around ,so that everything was lit well(that sucked, w/ mixed results). Then I tried to give things slightly differant colors, so you could differentiate them from one another. Still mixed results, and all my models looked funny because I had to use lots of colors.
Then I learned to use the ambient layer light, and add textures to my models. WOW!!! Now I can see what I'm doing. It really brings the renderings to life. Then I started to set textures to my classes(ie. walls), and now they are automatically drawn with textures!!
The great renderings aside, there are two other great things about 3-D.
1- Customers do not see things well in 2-D. Roll a model around for a customer, and they can see it much better. Better yet take them for a virtual walk thru. As a builder that does my own construction drawings, I unintentionally upstaged the Architect, when the Home Owner requested a walk thru, and the Architect wasn't able to do it with his software. They were very thankful, and impressed.
2- This is one of the biggest things about 3-D. I it use to rotate complicated drawings around and find the funny areas, were things come together...
Hope this wasn't too long winded, and helpful,
D-