If yours works as good as mine does, you will love it. Mine is actually marked Sig-Sauer 1911-22 but in reality it's made by GSG and the magazine is marked GSG rather than Sig-Sauer. The only difference appears to be the markings and the importer's address. Apparently GSG made some for Sig to import under their own logo and the other ones were imported by ATI.
The weight & balance of either one is very close to that of a .45 caliber 1911 and the magazines are made heavy enough to mimic a loaded .45 magazine. I can get better than 2" groups at 25 yards with Federal bulk pack "match grade" ammo from Walmart and in about 700 rounds down range, no malfunctions so far.
I like the threaded barrel too. Easy to put a suppressor on it if the ATF ever takes them off the NFA list. Don't think I want to go through all the hassle to own one with all the present red-tape but for those that are willing to jump through all the hoops, they are quiet enough to make it very pleasant to shoot even with out hearing protection.
You might have to change the front sight to set your point of impact, but they give you all the right allen wrenches to do it. Don't crank the set screws down too tight though or you'll strip the threads out of the plastic sights.
Someone told me that Novak sights will fit it, but I haven't tried them so you're on your own there.