Combat system...

I think that Tenebrous' new video goes into great detail about this and common stereotypes about it. I would say that I prefer the 1.8 system, but of course it is completely up for debate and is down to a person's personal opinion.

One thing that I and lots of other people have been suggesting is a /gamerule or some sort of command or configuration that you can do in game or on a server for you to choose the combat system. The reason why I say this is because at the moment lots of servers are just using 1.8 and then using a plugin like ViaVersion to make it compatible up to 1.12.2.

You can also use a 1.8 server version with ViaVersion and ViaRewind to make the server compatible for players 1.7 - 1.12.2 as lots of people still like the way that 1.7 works and looks and still use it.