I'm by no means a Kool-Aid drinker when it comes to servicing my bike. I don't believe you have to use Castrol, a quality filter will serve just fine in lieu of the BMW filter, and so on.
However, when it comes to the oil viscosity and rating recommendation, every oil marketer offers the viscosity and ratings that BMW recommends. I can find no compelling reason to deviate from those recommendations, and I would also question a dealer that deviates from them. Further, I'd wonder what other deviations or shortcuts they're taking that I don't know about. It just seems odd that a dealer would not follow such a basic recommendation.
As to DR's express qualifications, I'll leave that to DR. Based upon my limited experience on this forum, one answer I can think of is 'Someone who clearly knows more about BMW motorcycles than the rest of us will ever have a chance to learn'.
Edited by Tom Schmitz (03/21/12 10:21 AM)