I wouldn't call the conditions here "extreme", but I assume you don't get any salt and grid etc on the roads in winter.
I think it is very poor. Compare it to my mates KTMs, and the engine of my bike looks very tatty. They ride it in the same conditions, and follow similar cleaning etc.
The paint on the engine started to bubble at around 2 years, from then onwards, there was nothing to do about it. I clean the bike and the paint just flakes off.
I think I'll have to get somebody to re-paint the engine after this winter if I decide to keep the bike. I don't really think that's exceptable for a 3/4 year old bike.
It's a shame really because I think it's a very reliable bike, but the build quality is in places inferior to the competitors. I wouldn't have mind spending a few more quid for a bit thicker paint and silly things like decent hose clips so they don't just "fall off".

I hope Yamaha get their act together when they release a bike competing with the 990SM ... keeps dreaming