Well I'm playing on quick (latest patch) and about 180 turns in at the Renaissance era. The game has definitely improved since launch. The fact that I'm this far into it without vomiting is proof
Production seems normal now and there's actually tile yields worthwhile. The buildings I've constructed have counted for something. I haven't noticed any slow downs on a large map yet, I only have 4 workers though. Overall the game is more engaging then before, I have actually continued to play a few more turns to see what happens.
I'm amazed to see the queen with a navy!
All the AIs I've encountered aren't so quick to war with me and have had successful luxury trades and research agreements with 4/6 of them. Surprisingly I've been able to play the fence trading with one AI who didn't like the other and vise versa without pissing the other off.
AI does get pissed off quick though, at least with Suleiman whom I was friendly toward and then went downhill in 2 turns after I asked him to stop building next to me. He asked me the same thing near the start of the game without any problems.
That said it's still dumbed down/"streamlined". No real feedback on what the AI is thinking and limited dialog. They haven't fixed the silly 'the people who like shiny things the most" lists. Unless I'm missing a screen or two I can't really tell who is in the lead and who sucks the most. No wonder movies, no epic feeling of building a great empire, and the interface remains the same, simple yet complex with no double clicking or whole unit selection.