I never played w/ synthetic much, but I been a Dino.....not mixer as much as a "brand changer" all my life, still am. Whatever name brand is on sale......or cheapest is what the vehicles get. Seems that Dello LE has won out the last couple years,...Havoline before that, w/ Rotella inbetween a time or two. I've run SuperTech when all others were overpriced. And thru it all, in 55 yrs, I never could "wear out" an engine.
The motorcycle started w/ Havoline Syn, but w/ the wet clutch stories here, it perdy much stays w/ Rotella now.
When it come to adding a quart tween changes......if that ever happens, it never did matter what name was on a can/bottle.
Back in my young days.....60s, motors even got some tranny fluid now and then