I have both so I'll chime in.
The norc 1911 is a builders dream. You can get a pretty nice trigger pull buy just polishing and tweaking the stock parts. But like all 1911s, it can be a gun that requires tinkering once you start messing with it. I have one in 9mm and .45. My 45 is stock besides a little polishing. My 9mm is modified quite heavily. All internals replaced, about a 2.5lb trigger, some frame work and a hand fit match barrel and bushing. It now shoots much better than I'm capable of. lol
The Norc Sig is just like your typical Norc. Fit and finish isn't the best but it shoots fine. The factory double action is stupid heavy compared to a real sig. To the point it's not really fun to shoot double action. But luckily most sig parts are a direct swap. Only thing left norinco in mine is the frame, barrel and locking insert. And maybe the takedown lever, I can't remember. Like it has already been said, Sig mags don't fit directly. The frame is a little too long to allow a sig mag to get high enough to catch the mag catch. My solution was to throw the frame into a mill and I took off approx 0.020 off the bottom. Now sig mags fit and feed just fine.
Overall, both are great guns for their price. It's all up to personal preference.