Placing districts and wonders throughout your city's workable area makes it much more realistic and adds to the immersion in my opinion. I also really like the 'district' system. Having the ability to use faith to buy buldings and units is a nice addition too. I find the different tiers of religious units and the religious combat system to be cool and fun. The religion system is much more robust and interesting. Combat is almost always a multi turn process now (unless one of the combatants is an era or two above the other on the tech tree) and giving cities their own built in defenders was a welcome change for me. Though it was sort of annoying at first, I actually kind of came around to the combat style of Civ 6. Obviously Leonard Nimoy was the perfect person to read the new technology quotes, but Sean Bean is pretty great in his own right.

The sound track, the ambient sounds, and especially the combat sounds (no more annoying horn sounds when you win a round). I find the sound to be a HUGE improvement. I've seen a few people ask about how they compare so I figured I'd share my thoughts as a long time Civ 4 player who has recently started on Civ 6. I just downloaded Civ 6 with the free promotion from Epic games and spent the last week playing it.