I have the same background as you. Preordered it and never played it until now. Something is definitely missing. I played countless hours in X-Tension / X2 / X3 / AP / TC - but X Rebirth is really different. I will play definitely the campaign to its end (even though Egosoft is not really famous for producing deep campaigns). Maybe when the campaign ends the real free game begins...

I would say: Give it a try.