i finished this game aproximately 20-30 times by now (515,6 hours) ... And i can tell you with one hand on heart and another on bible, that in every single gameplay i find at least one thing (no matter if that was conversation, some alternative option to solve some quest, some artefact i didnt know about) that i had no idea until then that it was there.
That's impressive, Ragnarok. It makes me wonder, though, how differently we're experiencing the same game. To me, the prospect of such a small a discovery wouldn't warrant a new playthrough. For example, I anticipate playing two new games in patch 6, one with each sorcerer subclass (yay, back on topic!), but then I'll be done until patch 7.