So what changes does completing the coil bring?

I know that the recent 3.4 addition to the main story changes based on if you have completed the coil or not. But what is this change exactly? I have been holding from doing the main story because I am afraid I will miss some stuff because I have not completed coil. But then again no one does coil in my server so I am stuck in turn 5.

It's nothing major. The only difference is that certain characters will reference the events of the coil storyline.

The coil storyline is seperate from the Main Story,
like Mholito said there is small references here and there but nothing major