I bought and used a competitor, Punch Home Design Studio for a while. Punch is a semi-modernized application with a crusty old core ported from Windows.

I found Live Interior 3D to be much more satisfying... faster to render 3D views with lighting, walkthroughs in 3D. And the shaded renderings are stunning: everyone including our architects ask us what program we use.

The price is miniscule relative to the cost of a home renovation project. We found that it truly helped us to feel what the space would be like and to make dozens of "what if" changes.

It is great being able to download 3D models from Google (http://sketchup.google.com/3dwarehouse/). We were able to find many models and add them to our design.

There are bugs, sluggishness and awkward UIs. But the program is in active development with frequent updates and they seem to listen to customers. So hopefully they will continue to work on stability, performance and UI efficiency.