Completely agree with the OP, I have a 5906, and have owned a 4566TSW. They are two completely different beasts, they are also not build on the same frame, and I agree to it being the shooter issue. As with my 5906 with factory fixed novak sights, it hits POA at 10 yards perfectly, but with the 4566TSW my targets at 10 yards looked like I was shooting buckshot. Even tried 3 different grips styles on the gun, and still couldn't get it right. Sold it and bought a S&W 1911, right out of the box with a gun I hadn't shot before I was grouping and hitting POA.