I am an experience computer user, I design software for a living.
My interest is house design and conception. My wife and I have built a property portfolio of houses for a pension.
IMHO Sketchup is not good for House or building design. I use Arcon myself, it kicks Sketchup into next week as far as I am concerned.
However for conceptualisation and 3D illustrations Sketchup is awesome. I use it for all sorts of things, studwork, kitchen layouts, bathroom layouts. I get the drawings for the baths,units etc and make them in Sketchup, I can then see exactly what they look like. I make 3D drawings for my contractors so they can see exactly what I mean.
I found Sketchup hard to get into and still run into problems. Compared to Autocad it is easy. You get out what you put in.
Maybe one day I will be an expert like some of the people here but in the meantime I will carry on trundling out wicked 3D illustrations, get a buzz out of every one!
Peter