I liked the San Andreas duel weapon function though it seemed a bit of a poison chalice.
I always enjoyed using a single Colt pistol and Submachinegun, and so would like the option of switching between single-weapon and duel-weapon modes if the feature is implemented in VCS.
Another thing that annoyed me was how CJ would seemingly pull the other weapon out of thing air once Hitman level was reached, and also how the ammo only went down in single bullets when firing two weapons rather than two bullets per shot as it should have done...