Iptables Basics
jvns.ca
jvns.ca
It might take time for it to gain the same usage as iptables, but it is currently a drop-in replacement for iptables on many distros. Relevant discussion here: https://news.ycombinator.com/item?id=14286016
Also: https://developers.redhat.com/blog/2016/10/28/what-comes-aft...
iptables is old and awful.
nftables has been around for quite some time, and is now part of pretty much all distributions, including Debian. It's way cleaner and easier to use.
There are no reasons to stick to iptables in 2017.