The 450 was born and bred for the man who does not rload but wants hosspower available over the counter. They did it, but of course there is a price tag.
Either, with hopped up loads kicks like 10 Russian mules. Neither is a long range number. Both are devastating killers close up.
As mentioned, components are far and away easier to get for the 45-70, and, less expensive.
Me, I'd go with the 45-70, but that's me. If we all thought alike, believed the same stuff, this would indeed be a boring world :wink: