I could see some guys testing out some big bores in prep for alaska/africa, I mean aside from the range, what else are you going to test one of these big boys out on before a trip like that?
Aside from that I'd probably not have a .375, 458 as my goto deer rifle...course I'd take a .375 here in IL anyday over a slug.....but we're stuck with slugs...
my cousin, who's been to africa etc...., the 375 was the gun he bought for his safari, fell in love with that particular rifle, and now uses it on just about everything, used it on a mtn.lion! He says how well the gun fits etc....so if the gun fits? haha. He's also lost a giant black bear with a good shot from a .300WSM he said, after that he's kinda fine with overkill.