I put one on my Epiphone SG, but like you I was doing it at the same time as replacing the awful vintage style tuners. I suspect improvements were down to the new pegs, not the butler, but stability did improve.
Next time I change strings I’ll be taking it off to see if it was worth it. Shallower headstock angle on Epiphones is why I suspect it won’t make much difference. May be different on Gibsons.