How often do you use the pre-built rooms?

I use the styled rooms quite frequently, when I want to do something quickly, but I don't place the actual room. I just pick a room that comes closest to what I want and then I grab the wallpaper and flooring and a few items and place them how I see fit. Then I change a few things around and add stuff. That way I can furnish a bathroom or kids room in a few minutes if I don't have the inspiration at that moment to come up with a whole deco scheme of my own.