All previous oil changes on my '06 have been done by the dealer and I've always had coffee grinder to some extent. On one of those previous dealer oil changes I paid for the full synthetic (Castrol I believe). It greatly reduced the coffee grinder, but did not eliminated it completely. The full synthetic also seem to have much smoother shifting, but it was expensive and overall didn't think the added prices was worth it.
I've heard good things about Rotella's T6 from this forum and others (it is very popular with bikers of all makes and models), and wanted to try it. So, I recently did my own oil change with Rotella T6 to see first hand if it would solve the coffee grinder issue. Prices was right at $18/gallon and $6 for a Bosch 3323 oil filter making the total half what the dealer is charging. However, I had similar coffee grinder results as with the dealer's synthetic oil; greatly reduced, but not eliminated. I was hoping that it would improve over time, but perhaps not according to your results. However, for the price I think it is a better deal, for me, over the dealer oil change.
Side note: I used a Bosch 3323 oil filter and the oil light goes out much faster than it did after a dealer oil change (using an OEM oil filter). I don't know if that is due to the Bosch oil filter (i.e., larger capacity, better flow, anti drain back valve or some combination), the oil (5w being a bit thinner when cold) or both. Either way, I like it.
Chris Glennon - Portland, OR