Im gonna chime in here ......imagine that !
When you talk about "top shelf" stuff.....that's stuff that has been treated to the highest degree of workmanship......
some of us like "top shelf" alcohol ....and dont mind paying high dollar for it, some say that it is smoother and blah blah .......
Oil is similar to that stuff, some oils have more research done on them, and by doing more R&D, more things are "worked" on - thus, cost is up for that product and it is considered a "better" product.
I have run Mobil 1 ...for 35+ years.....never a problem, love the stuff, can walk up wally worlds shelf and get me some....sometimes on sale for $23 a 5 quart container....now - is this stuff "bettter" than Pennzoil ? ....not sure.....not ever sure at all! But the Mobil 1 does what it says ...I "trust" it to do the job and it has!
Moving on --- Amsoil, this is by far the gold standard when it comes to OIL, I dont give a shyte what you compare to it ....the Royal Purple the Mobil 1 the anything else ....AMSOIL IS better - period. And it cost more too!!!!
Amsoil does more research and more R&D than the others, and they have been doing it longer too - their stuff is that good. Now - are you going to see a difference? I bet not, is your oil going to last longer?, yes - perhaps a bit longer than you might think.
Here are two true God's gospel true stories......
Kubota BX25D - took stock hydraulic oil out, and replaced with S-UDT2, unbelievable difference........that was simply going from a non synthetic to a synthetic oil. Audible and functional difference.
2017 Subaru, stock oil, ran for 5k, changed to Mobil 1, at 12k changed again, and at 18k changed to Amsoil....... all the same oil eh???? Ok - here comes the weird stuff......engine sounded a little more quite - I know, I am getting old and cant hear, seriously - it sounded "smoother"...... I was getting on average 37.5 mpg when going to lake and back.....non 38.5 ....huge difference??? Perhaps not, but I can hear and see a small amount of change - so my pointed head rational is that something is going on differently.....
Draw your own conclusions - however, until you "try" it - and by whatever "it" is .....dont mock it!!!! Hell I remember a day when I would not eat quash .......love that stuff now!!!