Look at Rogan's site.
The only real advantage with .454 versus .357 is that if you miss the head altogether, you can hope the .454 will smash a shoulder all to hell and slow the dang thing down.
But that ain't a sure bet, not with .454 if we're dealing with a full-size Griz! If you really make the REAL headshot versus bouncing something off that upper armor, a .357 will be identical to a .454 in terms of results.
So...with .357, you'll get faster follow-ups to try and make that "true brain shot stopper".
So I've got a 1,500lbs monster charging at me. In .357, I've maybe got TWO chances at a full stopper shot, versus I can get one .454 round off due to the difference in recoil recovery time. If the .454 misses, it MIGHT slow the dang thing down...or it might not.
See why the .357 starts looking good?
Point two: in a strong gun like the Blackhawk, Redhawk or N-Frame with a 5" or so barrel, you can load .357 158 hardcast out to 1,500fps. That's on the low side of .44Mag factory energy levels. Given it's smaller bore, that's gonna be a deep-driving load, capable of making that long run up the snout and into the brain even on the biggest "teddies". Won't penetrate the "forehead" but for reasons of weird Ursine biology, 7mm Mag rifle is iffy too on that shot.
And then you're also carrying a nice general hunting/survival/defense gun.
If you're fishing/backpacking/motorcycling in the back country and want to pack light with a single do-all gun, methinks a good .357 has merit.
Jim