Accuracy?
Howdy megcatia,
On an intrinsic level, assuming both pistols are correctly fitted...none.
On a practical level, the 3/4 inch shorter sight radius will make a little
difference if you are shooting at a paper target...but very little difference,
and that's a matter of geometry. The shorter the idstance between the sights, the more deflection on the target for a given amount of misalignment of the sights.
The Commander variant of the 1911 is not, and never was intended to be a target pistol. (unless we're talking about the Gold Cup Commander, which is neither fish nor fowl.) Neither is the standard Government Model, for that matter.
The Commander was intended to be a close-range defensive pistol, and
its two advantages over the 5-inch gun are a better balance for some shooters...and it's a shade quicker out of the leather. The first advantage
is largely negated if the Commander has an allloy frame.
I like Commanders. The lightweight version is as close to an ideal carry gun
(for me) that I've ever handled, and the top-heavy aspect doesn't bother me at all.
Luck!
Tuner