I can speak for the GSG (although I have the Sig Sauer version) to report that is a reliable, accurate and easy to use gun. It shoots whatever ammo I put thru it. It is 80% swappable with 1911 spec parts, so if you want to customize the gun, it should be easy to do.
Field stripping the GSG is slightly different from a spec 1911 with an extra pin & allen screw to secure the barrel. The Umarex/Colt and the Chiappa have fixed barrels. (I also have the 2 versions of the Chiappa). The Chiappa does not have a grip safety.
For overall performance, I give the GSG/Sig 1911 22 the better shooter, and darn fun to shoot.
Don't let the zinc alloy throw you off, you can't expect a 22 caliber to move as much heavy steel as a 45 cal or 9MM can. The alloys holds up fine with the 22 cal.