I had a .458 x 2" American for time. I never really convinced myself of the need with its only redeeming virtue being its ability to be used in a bolt gun whereas the .45-70 is a little more problematic in bolt guns. I never got performance that surpassed the .45-70, only equaling it and then only with lighter bullets. The smaller case diameter gave it less internal volume than the .45-70 so the .45-70 in a strong action easily surpassed the .458 x 2" especially with heavier bullets.
Like you, I love the .458 Win Mag and find none of the faults commonly spewed about it. I can get 2100 fps with 500 gr. bullets and for anything that walks in North America that is plenty enough. Use a 400 or 450 gr. bullet and you can get 2200-2300 fps without the severe recoil of the .458 Lott pushing a 500 at 2300-2400 fps. While that extra ommph might be nice in Africa, it is pretty much wasted in North America.
And then the .458 SOCOM. How sweet is that round? Near .45-70 performance with light bullets and not too shabby with heavies and all that in a very accurate autoloader? Man, what is there NOT to love about that combo? 250 gr. at 2060 fps, 300 gr. at 1780 fps, and 500 at 1330 fps. That is a lot of power in a rifle the size of the AR. While it will not equal the .45-70 even in my 15” Contender, it comes close enough and you get a semi to boot, not a single shot.