Have had a DC02 for 13 years. Unbelievably good, has been dropped down stairs, fallen out of the car, been used to hoover up oil, petrol (by accident; was trying to sypon some), pond water, building rubble, can strap it to my woodworking kit’s dust extractor and leave it running all day and it just keeps on going.
Me bro has a DC23 Animal which is just as indestructable.
Me mum & dad have a dc01 which is complete trash: clogs all the time due to the shape of the air channels, changing the belt requires an MEng and the hose suction power is limted by a stupid safety valve. I’ve heard similar reports about most of the uprights.
My gut feeling is that the cylinders are ace and the uprights are overpriced landfill-in-the-waiting.