I used mine on dirt every time I rode it, I live on a farm.
The issue is with the airbox lid that doesnt seal propperly. No amount of grease seems to solve the problem. I had just under 10 000km on mine when it would not start. Now I have to convince the dealership that the dust might have damaged other engine components and that I need a rebuild of the motor at the very least to give me piece of mind while riding in remote areas. I was planning on riding the length of africa with this bike but if it lets me down in the namib dessert I am pretty much screwed.
But let me reserve judgement until the dealership lets me know what they are going to do about it.