Could someone help on explaining the advantage of iptables NAT over the netfilter hooks. Say suppose, instead of using NAT if we create custom kernel module to bind handler with netfilter for PRE/POST mangling, then in general which method (NAT/NF) is more optimized or regulated one ?Any links or pointers will be helpful. Thank you.! 
(S/D)NAT over NF hooks
linux;iptables;nat;netfilter