I have read thru some of the long term studies by Shell and I have personal experience with the Shell Rotella T6 5w/40 in my ST1300 , as mentioned after 200,000, everything was quiet
I don 't know if the quality of the oil had anything to do with it but the valve clearances were done at 28,000k (only 3 were adjusted) and at 220,000 I checked them and all were well with spec. I did this every fall so it was ready for next season
I used a go/no go gauge so even I could not get it wrong , at one point I was concerned I was doing it wrong so my Helicopter mechanic brother in law confirmed I was doing it right
I also pulled a trailer with the ST for 2 trips around NA and it had no impact on the clutch either
thanks R6