We have 5 of them spread across the family. Every one works brilliantly and none have had any faults, or any new filters. They have rippled out across the family as members have seen them in use, and realised how much better they are than anything else they had been using before. They can be found for a lot less than £250 if you keep an eye out -- none of ours were more than £150 brand new.
One in particular, a DC04, has been extensively used for building dust and rubble. It wasn't bought for this purpose, but it worked so much better than anything else that it got dedicated to the cause. Over the years, Dyson have continously improved the range with large increase in suck and ease of use features -- something which other manufacturers had seemingly given up on, and now play catch-up in so far as they can without patent infringement.