I was at the range today with a few guns, one of them my GSG 1911. It only works well and shoots accurately with CCI Mini Mag ammo. I've got one of those flip up targets that resets when you hit the centre swinger. Duck soup with the GSG, but only if I use the CCI ammo. Feeding is not 100% even with the CCI ammo.
What is missing is a good trigger pull and the weight of a steel 1911 frame. The trigger pull on my GSG breaks clean but on the heavy side, which is easily overcome with some concentration. Maybe that's a good thing ....