Is it really worth it is the question, well in my opinion, not really.
At the end of all debates, if you put the right sized shot in the right place, the bird will fall be it with 30 grams or 60 grams.
Realistically, you need to decide what is going to pattern best for your chosen birds, i.e. ducks and geese.
3 1/2" shells will put a large amount of shot in the air but the shot string is so long, double what should be going through a 12 bore, they're not going to throw the best patterns. Not to mention the very long chambers causing slight issues when shorter shells are fired, i.e