I have been looking for the same thing. I have a Smith and Wesson 22A that I am ready to part with. I have been looking at going the Sig 1911 or Ruger MKIII route. Still not sure which one to go with, but those GSG's look very tempting for the price. Good to know that people like them.
The Sig, GSG and ATI 1911-22's are the same gun, based on what I've read. But if you want ODG, FDE or the different grips, you'll have to go with the Sig.