Just purchased one of these Flymo Pac A Shred Shredder today after killing a cheap 'Pro performance' cheapo shredder. It will chop anything you throw at it and it's quick. The mechanism uses a sharp toothed gear which seems pretty robust. It folds away neatly into it's own box and has wheels to get around on.
Would say it is generally heavier than other shredders I have seen probably because it's built like a tank.
Definitely would recommend.