I honestly think if you're finding it easier to aim without the PAC, that you're doing it wrong :). Are you deploying speedbrakes on your gun runs by chance? You shouldn't be for PAC to work properly. Either way, you should post a track of a gun run with PAC enabled, as I really can't fathom how anyone could think that aiming without it is actually easier :).
EDIT: Upon closer reading, I see you're engaging multiple targets on a single gun run. I can see why PAC could be a disadvantage in that scenario. However, if you're targeting individual targets which require very accurate fire (like tanks), then PAC is absolutely indispensable IMO.