While the release might be full of bugs, just by the little information that we have right now I can tell that this is probably going to be a great title, if only due to its design philosophy.
Where one could easily tell that vainilla civ 5 was going to become a simplified, ahistorical tabletop warmonger game, even before its release, you can also see that civ 6 is going to be almost the complete opposite: A complex, flavourful, deep strategy title focused in building a civ and roleplaying it, with most of the series weak points being adressed and exciting, new design ideas being put into play:
- Making AIs to roleplay rather than play to win
- "Geography means destiny" being translated into game mechanics
- Moving away from "science beats anything else"
- Refining and fixing 1UPT
- Re-introducing goverments
- Increasing customization and min-maxing via city districts
- Having most features right out of the gate (archeology, spyionage, religion, etc) rather than having to wait for expansions / DLC in order to have a complete game
- Tons and tons of flavourful dettails that will add variety and replayability to the game: A land's appeal and beauty influencing the game, unique abilities for city states, unique great persons... so, so much to experiment with!
I completely expect to be blown away by it and to see civ IV surpassed! Make it happen, Beach!
I think fine balancing is beyond most developers' abilities. Working inside the game's framework to optimize is pretty different from creating/programming it, it's rare to find developers who can play at anywhere near the quality of a game's elite players, in any game. They usually have the knowledge to be significantly above average and that's about it.
I think that this is a pity. I mean, strategy games, unlike, say, third person adventures, lives or die due to game balance. If they are going to tunnel resources into some area, it's gotta be this one, I think.