The Truth About Guns did a pretty in depth review of the Sig 1911 Nitron (the "basic" model). The condensed version is; when it runs it's great, but it doesn't run.
I appreciate the blogger's honest observations. However, as with any gun (and any product), you can't rely on a single review or even a couple of reviews. Everyone makes a lemon. The questions are (1) how many guns have significant problems and (2) what does the manufacturer do to fix it.
I have a Sig C3 (2006 0r 2007). After the first 100 rounds, it ran great. I learned that it came with a barrel that was part of a bad batch from the barrel manufacture. I sent it back on Sig's dime and they had it back in a week plus staked the plunger tube better. I carried it quite a bit until I got something I liked even better. It is now my "backup" carry gun in the even my primary gun goes down. I would personally not hesitate in buying another Sig 1911.