I just took delivery on my full size in.45acp and took it to the range 2 days ago. I fed it 150rds of mixed wwb and blazer brass and the gun functioned perfectly. After shooting about 2 mags worth of ammo to get used to the trigger, I was able to keep my groupings very tight. I have been a long time P220 owner, but I love this gun so much that it is my new carry gun. I plan to get the 3 other calibers and experiment with modding a full size gripframe to accept a compact slide. I am also going to purchase a few extra FCU's to keep as spares in case Sig stops making them. I feel that this is one of the most innovative designs in a long time.