Unfortunately I've just read a Czech first-impressions article and was pretty negative - complaining about "drastical simplification of the game".
Namely:
- lack of graphs and detailed data about other civilizations so you don't know how to behave - no info about leaders' attitude, mood, philosophy,
- simplified diplomacy "without maps", reasearch too easy (because you can easily research it with another civilization without any consideration to it's actual tech-progress) which leads to absence of thrilling technological races,
- no central administration of states money but on the contrary need to manually adjust each single city's money-policy
- and about civilian units changing automatically into ships: "they can travel to the second end of the world if necessary".
One thing they've praised was a combat system but to be honest, I am pretty worried about the game now.
but who knows if the article isn't too exaggerated
czech source here:
http://pc.hrej.cz/preview/prvni-dojmy-z-civilization-v-3215/