I am going to break the trend and go with the 454 mainly because I have about 10 of them and it will do anything the 480 will do. And I have a 475 limbaugh for anything else. Also because I love Freedom arms single actions and it's pretty easy to find them in 454.
If you have ten of them, you aren't bucking any trend. Why not step into a .480? There is one thing the .480 will do that no .454 will ever be able to do, and that is shoot .475-inch bullets! LOL!