Ok, so here's my experience so far..
In terms of performance, the game is inconsistent. That said, the game's lowest framerate is around towns and indoors. Surprisingly, the outdoors have the best framerate; whether I'm going into caves or scaling mountainsides, the performance is smooth. I've tried playing with the settings and nothing seems to noticeably affect the framerate in towns; I think it's a fundamental flaw in the game.
After finishing the prologue (Feshyr, the island from the demo), the story drops me off on the coast of a neighbouring land. This is where I begin to notice an issue that I would have never known from the demo (since the demo featured a very limited area with very limited character interaction); apparently all the NPC's (with the exception of the main story characters from previous Gothic games) are lazily repeated character models. Occasionally they change the headgear and clothing but they're just a bunch of clones. So that kinda sucks, especially that some of the NPC's are significant characters (kings, barons, etc.) and they all look exactly the same. That just really pulls me out of the experience and breaks the immersion.
Aside from those points, the game really feels like a Gothic game is how generic it is.