Here is my oil observations over the last two weeks. I have 14,500 miles on my bike and I have been using shell rotella (non-synthetic) for about 12,000 miles. I thought that it worked well but the clutch chatter was bad when cold and the shifting was always “stiff” especially when downshifting. When it came time to change the oil my local auto parts store did not have rotella so I decided to use castrol GTX 10w-40. After the oil change I made two round trips to Indianapolis and noticed that the clutch chatter was gone and the shifting was smooth as silk. Because of my observations I will not go back to rotella, but I will not say that it is crap in our bikes. I firmly believe that rotella is a great oil and it seems silly to argue about which oil is the best. It all boils down to personal opinions like which brand gas is the best