dyson's being used commercially
I used to use a dc33 for my mothers work, she works at a children's after school club so as you could imagine the corridor where the kids would play was not a pretty sight by he end of the night, but for about 2 years the dc33 was used everyday and didn't encounter any issue, I still have that dc33 but it never gets used now as I swapped it for my henry.
Another example I can think of was a dc14 was being used in my parents friends 3 story largish house with 3 men, 6 dogs and 7 cats, used everyday for nearly 8 years and didn't have any problems until it burned out in the beginning of this year, its filter only ever saw 1 wash so its quite a miracle really.
Thats the thing which annoys me with not just dyson but allot of brands is that they dont advertise any of the mantience needed for there machines.