I voted "Somewhat/Cautiously Optimistic".
Being able to combine units during later eras to reduce the "Carpet of Doom" created by large number of units in Civ5 is some progress.
The return of City Happiness instead of global happiness.
Wonders taking up a tile.
Buildings built on adjacent tiles.
Eureka moments.
However, as I watched more video clips and read further, I am becoming disillusioned.
Civ6 is appearing more cartoonish and simplified. Like Civ Revolution units in a Civ5 base game.
Only one leader per Empire.
So, I am expecting fewer units and complexity.
I liked Civ4s Rock-Paper-Scissors method to a point where I yearned for more complexity and now only play the Realism Invictus mod version which went further to a Rock-Paper-Scissors-Lizard-Spock style method by including a charge mounted horsemen line and extending the Recon units line to be better at attacking melee with terrain advantages.
They expanded the number of leaders to 5 or more, like adding President Polk and Teddy Roosevelt to America.
Even with knowing that expansion packs will come later as usual, I doubt I will see 3 or more leaders for an Empire.
So, my vote might need to be reduced to Somewhat Pessimistic.