Diamond Jubilee
I've had a DJ for a few years now, and I haven't had any trouble with its motor, nor have any of the other DJ owners I've known. The main problem point with the DJ was the bottom plate of the PN-5 power nozzle, which was plastic. The mounting holes where the brush roll bearing retainers are screwed into the plate tend to break.
There are no replacement bottom plates available. For a while, there was a redesigned housing available for the entire PN, but now Aerus has discontinued that, too.
A PN-5 in good shape is something to prize and take care of. It's an excellent power nozzle, so long as its bottom plate is intact and capable of keeping the brush roll bearings in place.