Human-level restrictions on neural processing are something you have not taken into account. In order to react to something, you will require approximately 0.33 seconds to process any sufficiently complex reaction (i.e. one that utilises the CNS over simple motor neurons).

Given the nerf, this is still not enough time to adequately react to a bullet being fired at you. You will be hit before you can react to it. Complex reactions - such as processing someone firing a gun at you - may take more time. Even if you have "advanced senses", your body still has an inherent lag that cannot be bypassed due to the process of using neurotransmitters and the nerve impulses themselves requiring this baseline of time to complete.

If you think that guns are remotely balanced without restricted projectile speeds in combat, you have not been fighting properly for the past <insert time you have been fighting here>. You have been writing prose.