My fairly new Roomba 570 stopped roomba-fying the other day. Their automated technical help was useless. Thank god for the internet!
What they refuse to acknowledge is that you have to be an ubergeek to own one of these, or be prepared to send it out every 9 months. Following the 'underground' instructions, I took it apart and cleaned out the gearbox for the brushes. It was totally packed with dog hair and dust! I don't think most people would want to do this.
My son lives in a university house full of engineers. Their new Roomba had a corroding plate, and they modified it to be better! Since that house is a filthy pig nest, they'll soon be tearing it down as well.