afaik.. Amsoil is high quality. I only use their compressors flud and it flows at 20deg plenty good enough to not trip any CB .
my old thinking is Mobil1 and then I found out from an independent chart that that Redline has more heat protection in the upper piston ring area. i don't know about other new oils.
that said they are both big marketing products. Lubemaster77 has product that seems very high end.