As Next Level correctly noted in this thread and as Zwill said in other threads, one of the big positive qualities of Butterfly rubber is its low weight with quite high sponge hardness. I noticed that several new Butterfly blades that passed through my hands began to weigh more than 90 grams, namely 93 grams! Good weight and balance of the racket is obtained with light rubbers from Butterfly, but putting two rubbers with a hard sponge from ESN or DHS will not work - the overall weight of the racket increases and the balance shifts to the blade, which complicates wrist movements, for example, when performing a banana and backhand topspin.
In this regard, thoughts may arise about a conspiracy by Butterfly, who deliberately increase the weight of the blade so that when buying a new blade, the player would sooner or later buy Butterfly rubbers because of the weight, but it still seems to me that in this way Butterfly simply balances the weight of its equipment. After all, if the blade and rubbers are light, then the racket will also be lighter and ultimately have no power.
Edited. It is possible that the high weight of the new Butterfly blades that I got is just a coincidence and I am making up something that does not exist, but here we share our personal experiences and observations, and for me it is like this for now.