I use Mobile Delvac 15w-40 conventional Diesel oil in my Goldwing and Suzuki Hayabusa. Worked great in both. Only UOA I did was this year after a 3500 mile round trip from Iowa, Colorado, Utah, Arizona and back to Iowa. UOA was great. Only notable section would be it sheared from the 40 weight to the high side of a 30 weight. Been using the Delvac in various bikes for close to 20 years and have been happy.
I have found for me personally, I do not like how the Rotella synthetic 5w-40 shears. Never had it tested but in less than 1000 miles, on any motorcycle I used it in, the shifting would become so notchy I had to change it out. I may be more sensitive to my shifts, I like to feel it snick into gear, not have to work at it to change into the next gear and sometimes feel it sort of hang up or mildly grind, only way I can describe the feeling. Just did not care for it.
Just my experience.