I've only had 1 DC50, as shown on here years ago, but with a blown motor, torn hose, worn brushroll and damaged cable, I felt I would be laughed out of the room if I tried a warranty claim! Only paid a fiver, and it came with a tangle free tool that I kept so not all bad!
Don't mind 40/41's so much, have had a few through my hands now and am getting the nack of refurbishing them (bar the yolk loom, sodding thing). Avoid DC24's unless their free though, too much expense if the main motor, brushroll motor and PCB have gone! Don't like selling them either incase they go 5 minutes after the buyer uses it. Have 2 24's, a blue one which if you follow my youtube channel you will have seen, that's going to Amys aunt as she lives in a 1 bed flat so it's a bit ideal, and close enough that when it breaks it won't be an issue. Got another bin find 24 that I have not touched yet, so will see how that goes!
Infact with 24's, I turn them on infront of the owner if I get one in for a refurb, and check the sparking. Nearly buggared myself up before taking in a 'runs fine, just no suction' one and finding out the motor was nearly dead... Luckily she agreed to a new motor when I sent her a video, but that could so easily have gone the other way!