I have experience with Sig Scorpion 1911 and NHC Predator. Both shoot great but the NHC feels more like a fine tuned machine.
My Sig had some fail to feed issues, but after a 15 min phone call to Sig they emailed me a shipping label and i had the repaired pistol back in 7 business days. I haven't shot it since but it came back with a note from the gunsmith who worked on it, stating what he found as the problem and what he did to rectify it. It also said that he fired 200 rounds thought it without a FTF, which i was unable to do.
The NHC hasn't had the slightest hiccup from the first round, it's been flawless. But i'm very happy with SIG's customer service and warranty