For myself (and probably the vast majority of handgun shooters) I don't enjoy shooting the hottest load I can stuff into my .44 mag or .45 Colt revolvers. The recoil and blast is not enjoyable to me. And I don't hunt with my handguns. So I don't give a hoot about which revolver has the ultimate strength or lifespan under the heaviest loads. Sheesh... the average gun owner hardly even shoots his guns!
But I get a great deal of pleasure shooting moderate to light loads in these big bore calibers. Unless one simply must shoot the hottest loads available in big bore handguns, the Smith and Ruger guns are both quite up to the task, so what's the point with "ultimate" strength?
It's like picking between two beautiful girls and selecting one of them over the other simply because she's a little stronger... if they both flip your switch, the strength factor generally doesn't really matter. (I do understand that the handgun hunter may be seeking ultimate power and strength, but that's a completely separate category of use which doesn't apply to most of us.) ;-)=
So what if gun brand A might need some parts replaced at 100,000 rounds and brand B might be able to go to 120,000 rounds before replacing some parts. What counts is how much you like shooting it, how much pleasure it brings you. Would you really even get close to using the gun to anywhere near it's lifespan?
Another example, let's just say for example that a Nissan Altima can go 275,000 miles before major repairs, but a Toyota Avalon typically needs major repairs at 250,000... would you buy the Altima and prefer driving it for all those miles just to get that extra 25,000 miles out of it... if you even owned it anywhere near that long? Either one will get you there reasonably well, but there are differences! I'd take the Avalon myself, and enjoy the nicer ride all along the way... who cares if the ultimate lifespan is slightly different? Or buy both cars and let them share the wear! ;-)=