I bought this to replace an earlier model. The earlier model was fine for a while but the battery needed replacing at about yearly intervals.
I finally got tired of the hopeless battery life and, with some misgivings, decided to update to this model, drawn in no small part by the promise of a two year guarantee. However, on reading the small print of the guarantee I was disturbed to see this exclusion:-
"Reduction in battery discharge time due to battery age or use".
So Mr Dyson, not really a two year guarantee at all. CHEATS!