I have fast twist 222, 22-250, fast twist 270 and standard, 338-06's, and a 416 Rem Mag. Each cartridge has at least one rifle threaded with the exception of the 416.
I use whatever strikes me. This year was 270, 100th anniversary and all. Next year thinking 22-250 for antelope and 338-06 for deer if I draw certain tags. Sure I will carry 270 at some point too. 416 is for Africa, or possibly elk if I draw a special tag.
I can't say I ever moved to smaller cartridges, since I started using the 22-250 and 222 twenty plus years ago because of all the naysayers said you can't, you shouldn't, blah, blah , blah. Obviously long since disproven. Mix in a smattering of 6.5, 30's, 348, 9.3, 375, and 404 you have a person with rifle/cartridge ADHD.