I want full voiced Tavs i believe it will give much more depth and weight to the fate of our characters. That doesn't mean that i am not gonna be happy if they aren't but it will be a pleasant addition to hear our heroes deliver their lines. Also we know it is a video game and not an actual dnd session so there are limitations just by having dialouges to choose from (like most rpgs). Not having full voiced Tavs won't change much as to the freedom you get to feel by playing the game and in my experience bg3 is already a pretty "free" game as to what you can do and say. 4k lines i think are just enough for the whole game (but maybe am wrong) because we deal with certain amounts of options in each dialouge scene,some have more some have less. Also i saw a comment on Josh Wichard's twitter post were he complements the games depth , attention to detail and writing. Now if he has an opinion on something like that to me it means he delved deeper into Tav than just voice barks and idle comments.
