I came back about a month ago. Ourouroubos has been my favorite. I started at level 30 and am level 41 and about 70% through 15-19. I really wish that was how you could play the storyline. It's fun to see the arcs but since they don't have any impact on your specific story, like loyalists vs resistance, it loses some luster.
But when playing normally, I realized I was just leveling too fast to go through the proper story mechanics. Going through the story the natural way is just too disjointed. I know I can stop XP and there are some guides but that's just not inviting. If they could make the story structure more pointed and "on rails" naturally, I'd be excited about creating new toons and making different decisions. It would extend the life so that when I do hit 50, I have more options to play through the story several times or do level 50 things.
I'm sure this has been brought up and don't want to say negatives about the time traveling, though. It's great and so much content.