I generally keep mine around, I have a display shelf for older versions of characters who have been 'superseded' on the main shelf.
I have mixed feelings about this term redundancy we use to describe luxury items like collectors toys. I get that we all sort of want the best representation of a character or toy from out childhood, but I feel like we often put too much emphasis on what a character looks like. Even a collectors toy should be a fun toy first, so even if I have a new toy that's a more accurate looking version of the character if the old toy is fun then I usually want to hang onto both.
That said I've been known to sell the odd few toys who were not fun to mess with.