While I disagree with the fact that the P47 specs were very close to that of the P51(they weren't),I must say that they do not compare.The jobs they were intended for was very different.
Besides,the P51 was USA built but english designed(the british had designed it as a replacement for the Spitfire but the british govt not having the necessary $$$+ the fact that the latest improved versions of the Spit were doing aprox the same,declined to fabricate it and offered it to the US govt who quickly recognized a good offer).
This being said,I reckon both Ruger and S&W are excellent tools.In my case,I'll say that I'm a revolver man(even though I have a long auto background) and,well....I love S&Ws!
Qc