I have A SIG GSR and it is scary accurate. However, I had reliability issues until Shane at Reliable Gun worked on it. Mine had a lot of razor sharp edges in the action particularly the extractor hook and around the throat which would catch the cartridge as it fed. Then my extractor hook broke because the metal was too thin and SIG sent me a redesigned beefier part (but I had to wait 7 months for it). After these 2 fixes the gun runs 100%.
There might be better choices for an 1911. Mine is great now but I can't speak for other GSRs. I agree with Colin that searching the SIG and 1911 forums is critical. The consensus seems to be that it has great parts and quality but reliability can be hit or miss.
After horrible customer service from SIG I am hesitant to get another. They basically ignored the Canadian Reps (FN Sports) emails and phone calls even though my extractor was covered by warranty. According to Reliable Gun, Glock and STI have the best customer services in BC with a strong local distributor (fast service and lots of parts) so my next 1911 will be a STI.