I have one made in May 2010, and have been real happy with it.
I had a few (4 or 5) feeding problems at first, I called SIG and had them send me the new flat wire recoil spring. I also bought two of the newer (3rd gen?) mags. Since then I have about 200rds through it with not one feeding issue!
I also use the original magazine at the range, and don't have any problems with it, but I carry it with the newer mags.