The LGS where I work just got a Rock Island 1911 .45 in yesterday. No, I have not shot it yet but I found fit & finish to be good. Is it a Colt or Springer, no, but it looks and feels solid, slide is smooth and trigger is better than some more expensive 1911's that I have shot. Pricing is significantly less that the Ruger 1911.
Just first impressions what its worth, YMMV. Good luck with your purchase, whatever you decide on.
If I have to explain it, you probably won't understand it.