I fell for the B&Q too.
Fortunately mine blew up after 15 minutes. I took it back and the helpful assistant suggested I might not want a replacement - after all it was only a cheap B&Q shredder.....
So I bought the Bosch screw feed instead. It has been so easy to use and so enthusiastic that bits of shrubbery that have been annoying us for years have vanished and I have been searching the garden for more stuff to feed it.
OK so it was twice the price - but it WORKS - and works better than the one I used to hire at £30 a go.
Happy days.