I'm an architect by day (like real buildings), and sketchup is used really heavily in my field, cuz it just works. The problem with more advanced software is that with large teams, you'll get different people working in different ways and if 1 person doesn't conform to the standards, it screws up the organization of the entire project. You can't really screw anything up in sketchup since it's so simple. Also, Import and export between other programs works really well also, which is key. Components/blocks and whatever associations are often preserved.