My favorite double is a 450-400-3", and has been for years..I have used the others and find that kind of power unnecessary..
However, my other favorite caliber in doubles is the 450-3.25..Its a great caliber and recoil is a bit less than the 470 it seems to me..
They are all good, and you should pick one by your ability to be honest with yourself as to how much recoil you can tolerate and by that I mean that you can shoot as well as say a 222 or 243..
Too many shooters think they can handle recoil that they cannot, they believe they don't flinch shooting at game, but they do on targets or off a bench..Thats all BS boys, you can either handle la rifles recoil or you cannot..If one shoots a LOT then he probably can handle the big bores.
I can shoot any big bore, been doing it for years but I do not enjoy the 470 and up and I have to "concentrate" on not flinching..With the 450-400 I just shoot it with no more concern than I shoot a 22 L.R. therefore I see my limit is the 450-400 for the most part and its served me well on Buffalo and even elephant to a somewhat lesser extent.
Bottom line is one does not need more power than a 450-400 on this planet IMO.