We've had one for a couple of years now - it gathers dust most of the time but when we do do a purge of old paperwork I feel much better having shredded it for privacy reasons. I only use it for bills, identifiable paperwork etc

It was a real cheapie on sale (around $30 if I remember) and it can be a real PITA because you can't do more than about 5 sheets and it can't run for more than a minute or so without a minutes rest. Shredding a big pile can take a while, but you get what you pay for I guess! Either that or I should clear out the study more regularly!