Rotella since it has the certifications. Last I checked, Delo did not have any JASO ratings at all for wet clutch/shared sump use. It may work, but why risk an expensive engine on a trial when you don't need to?
Used Rotella extensively in all my bikes, quads, and yard equipment over the years with zero problems to report. All except the old Harley I had because Shell don't make a 20W60 motorcycle oil for an old school Shovelhead H-D! Lol