Most FX Impact videos (and there are multitudes of them) focus on demonstrating how quickly and easily it is to change barrels (calibers) and emphasizing the versatility of Impact. But rarely mentioned is that once one changes the barrel (caliber), one must also change the reg pressure, the transfer port, the valve limiter, and the hammer spring tension; and after all of that, then one must re-zero the scope. That takes time. More time than is admitted in the videos. Were I to buy an FX Impact, I would have but one barrel and leave it set up so that it's ready to go in an instant. If I wanted a couple more additional calibers, I'd buy separate guns dedicated for each caliber. But not everyone can justify having a separate gun for each caliber. The FX Impact (and the Crown) has it's place for those who can't justify having so many guns but still need several calibers.
Using your own example: If your FX Impact (or Crown) is set up to shoot .22 cal., and all of a sudden you needed .25 cal. to dispatch a larger prey, if you had an FX Wildcat in .25 sitting right there beside your Impact, would you then think it a pain in the ass to switch barrels on the Impact? My guess is that you wouldn't even consider changing the barrel on the Impact, but would instinctively grab the Wildcat and do your business without delay!
For me, I have an FX Wildcat in .22. and it's ready to go in an instant. If I ever buy an FX Impact it will be for .25 and I'll leave it set up optimally for .25 so that it is just as handy as my Wildcat. But if I could only have one gun, I'd choose the Impact and get barrels (liners) for each caliber and just live with the extreme pain in my ass every time I needed to change calibers. And I'd also cuss a blue streak every time my prey decides that it's too big a waste of his time to wait around for me to change barrels and setups and re-zero my scope and moves out of range before I get it all done.