I'm about to buy one of the Rugers myself.
I'd love to be able to afford a double in 450/400 but it's too much and the Ruger is a super strong action.
That means that, should a handloader feel brave (or silly!!) enough, there's more performance to be had from 450/400.
It could probably be loaded to give a better trajectory.
Mind you you'd need to do something about the recoil.......a Limbsaver pad at least.
On the other hand it can be loaded with 41 cal pistol bullets, like the Sierra 210gr JHC, and a friend of mine has had a great deal of fun doing exactly this.
Cuts down on costs and allows practise with the rifle on targets and small and medium game.
Not exactly what the designers initially meant for this cartridge but a chance to use it on a regular basis with out needing shoulder surgery!
It would be good to some lighter, pointy pills come out for this calibre.....say a 300gr or 325gr spitzer or mag tip.
It could probably be pushed to almost 2400fps and favours Ruger No1s more than doubles as they don't have the fixed nature of barrel regulation.