After one and a half years of good cleaning, my Dyson started to not make it back to recharge and 'malfunctioned' only after a few minutes.
Watching it, it would go around objects in one direction or get stuck up against walls for no apparent reason.
Close inspection found one of the tanktracks was just spinning, causing the Dyson to stop with and error after only a few minutes.

Being sent back under warranty. This clearly is a 'wear and tear' issue and am hoping Dyson have already recognised this and improved the materials involved and that BOTH my tank tracks AND teethed small cogs are changed.

Perhaps the initial set up always meant it would clean each patch in once direction, thus causing wear faster on one track.