I agree both are good calibers, but the Casull wins out IMHO hands down.
The 445 is hard to get ammo and brass is even harder.
The 454 's factory ammo is available and brass is readily available.
Performance between the two is a moot point. Either will fit the bill.
Personally, I have never been a 44 fan, cannot tell you why... I always remember a story about a man carrying a 45. He was asked why he carried a 45. He responded because they don't make a 46...
I have a 454 in a CR carbine and love it. I have been shooting game with heavy loaded 45 Colts in both rifles and revolvers for many years. I have the utmost confidence in it.
CW