I got about 4 games into Civ 6 before my joy of it started to drain (it'll come back, though) and overall I think it is a good game, and at least as good as Civ 5 was when it came out. I have a few issues with the game for balance, and the AI has all the same issues as before (actually, even worse in the first couple games I played!), but in a lot of ways it is a step up.
Things I like: The religion and great person systems are a lot more interesting than "oh look I got a thing". The espionage system is closer to Civ 4's than 5's, but a lot less tedious so an improvement there too. I like how every resource you collect (from culture to wheat) seems to have a place in the game beyond "oh yeah, you get +1 food. woo". City States are more interesting and MUCH more proactive than in 5, so love that.
Things I dislike: THE ART STYLE FOR MOST OF THE GAME (seriously, me no-like the cartoon-ish aesthetic). The AI gets real dumb a lot of the time, with one city state making so many archers and warriors that by the modern age they covered literally half a continent around them (not joking one bit). I get the distinct feeling that the difficulty level from the mid-level difficulty setting is entirely the AI cheating and not anything else as I have seen civs raise armies of 5 or 6 units in the first 20 turns (the earliest war that has been declared on me), and I find that extremely annoying. The endgame feels more like a slog than usual, without feeling like you have enough time to really accomplish anything. The victory conditions, while they have added some mechanics behind them feel almost as hollow to me as in Beyond Earth, especially the cultural which just kind of has you winning out of nowhere.