Been playing since Day 1 of Civ 1 (see signature). My mom came home with a demo (remember the 5 inch floppy disk?), I got to play Greece for a few turns (and yes, Alexander's empire was pink). Never looked back, through CTP, Civ Rev, and all the standard iterations.
Each new Civilization game has brought new ideas, some good, some not so much.
Overall, though, I think this one has many ideas that I am excited about. Unstacking cities? Big positive. I always try to have many wonders in many different cities, seeing one capital with 12 wonders was always a little immersion breaking. 1upt has its good and bad points, but I can see, if implemented properly (or well), a definite upside, especially with limited stacking. Always loved the new civs, leaders, wonders, and, in the last few titles, UUs, UBs and UIs that have been brought into rotation. I've been a huge history buff all my life, and Civ has helped feed that over the years. Though I would still like more than one SE Asian or Sub-Saharan African civ not named Zulu per game (but keep the Zulu!). I am excited about the government card system (3/4 of the real world today consider themselves republics, yet each has very different policies in response to their culture, history, and geography), and the culture vs. science trees for multiple types of victories seems impressive. Can they make naval warfare at least a little better? We'll see, but unless the devs don't read these posts, and I know they do, I think they will have something figured out.
I have no issue with the graphics, personally.
Now, I don't expect this to be all roses. At least, there are always a couple thorns (bugs) here and there on release. Still, given what Civ 1 originally started out as, and how it's morphed into such a complex (yet simple) 4x game, I am positive about Civ 6 overall being the best one yet. I generally haven't been disappointed, CTP notwithstanding (though it had its moments).