The "tick" rate of servers (how often they process the game world per second) can have a huge impact on overall hit registry and responsiveness of the game, I'd bet the server hosts are being cheap with BF4 and setting/leaving it on low mostly which would explain why some servers are much better than others in that regard.
Unless all clients are on <10ms latency your always going to have to make a noticeable trade between perceived hit registry and players being hit after they've gone to cover - there is afaik no way around that - however Dice seem to have somehow managed to get the worst of both which tbh takes some doing. Personally I'd rather "netcode" where I did get damage sometimes happening after I'd gone into cover as in most games it means you get great hit registry, not however BF4.
Unless all clients are on <10ms latency your always going to have to make a noticeable trade between perceived hit registry and players being hit after they've gone to cover - there is afaik no way around that - however Dice seem to have somehow managed to get the worst of both which tbh takes some doing. Personally I'd rather "netcode" where I did get damage sometimes happening after I'd gone into cover as in most games it means you get great hit registry, not however BF4.