That anti lag script will not make any difference. The callbacks that are hooked in that script are called when SA-MP thinks a player has shot another player and this is calculated based on 0.3z's lag compensation mode.
Edit: Looking at that script again, all it does is inflict double dsmage. Thats why you think the sync is so much better when using it.
Edit: Looking at that script again, all it does is inflict double dsmage. Thats why you think the sync is so much better when using it.