Genalex Gold Lion 12AX7 - different grades?

Hello all - I’ve been searching for a new set of tubes for my Manley Snappers and have decided to go with the Gold Lion KT77s & 12AX7 . One seller I like has referenced they have different grades "Gold/Platinum" of the 12AX7 , lower noise shelf , microphonics etc....is this possible or sales hype.....as I look around other sellers the 12AX7s all look the same , no classification differences...thanks