This is not a post about pros or cons on instancing. However, I found issues on how the instancing system works.
Instancing does not keep teams together very well. I teamed up with some friends, we gathered in the same Sector Space instance and entered a system for a particular mission. When we returned to SS, we found ourselves scattered in different instance of sector space again. I wish the system would be smarter to keep teams together between missions/episodes so we don't have to juggle with instance screens all the time.
When we switch Sector Space instance, it puts us back near Sol System (if you are in Sirius sector block). I wish we could stay where we were before the instance switch so we don't have to fly across the block once again. Especially given the first issue above where we get scattered around between missions.
So, instancing being good or bad for gameplay is not the issue here, but please fix the system as it exists right now in the game.