Say that this update ruined the server it's an exaggeration, there are some bugs that could be fixed soon but it's not a big problem, also the new damage system prevent damage mods or health hacks and now probably the server will not have that problem anymore.
Talking about the saw damage, you can do the same of "kills a player in 5m of distance" only try to give physical damage to your opponent and see that he will lose his health.
If you don't like the new update doesn't mean that other players don't like it, also I saw few players that usually, for lag problems, they could not give the complete damage to other players with the other damage system and now they can.