This is also a great tool to use if you are thinking about buying a house or moving and you don't know how the current plan fits your lifestyle. After spending a little bit of time you'll easily be able to gage if the space works for you as is, if you'll have to do renovations, how extensive they may be, or if there's so much work to be done that maybe the space doesn't work for you at all.
The room planner is really easy to use too. I tested out this kitchen concept that I've had in mind for a while. I've always wanted a kitchen with the stove in the island - that way you can cook and talk to people in the kitchen instead of having your back to them. Also, since the kitchen is such a social part of the house I put some big comfy chairs for people to sit and have a glass of wine while I'm cooking. It's so fun to design the fantasy life, and after this experience I'm ready to go house shopping again and find my new home!