1) No death in a single turn. I - so far - like the fact that units can survive more than one turn. This adds up to strategic deepness and micro management, enabling units to retreat, heal and then reengage.
2) Locked workers. I like the fact, that you can lock worker citizens as so to avoid rearranging them by the game. This feature is still not perfect - but a good Idea- since sometimes the workers are rearranged anyway. It should be fixed in a way that for example the moved resource is shown in read as to see which citizen has been moved. And then you could confirm the repositioning or change it.
3) Leader animations on diplomacy screen. Leader animations are graphically - and probably artistically - better (more detailed texture and model and better animation).
4) Fast turns at late game. Despite several's experience I've found the turns are faster than in modded Civ4 games. (This may mean nothing though, since I compare custom content with a base game).
5) Ranged attack. Although somewhat unrealistic, I still like the fact that units can fire from distance and that the missile volley is animated.
6) Road maintenance. Maybe I am alone with this, but I like the fact (if properly balanced, which is not the case now) that you need to maintain roads. This avoids the unrealistic and huge grid of roads at the end of the game. In Civ4 you can grid a whole continent without a penalty.
7) Great people can build land improvements. This is a nice feature, but must be better balanced.
I'm going to admit, I am very disappointed with Civ5. So I guess I fit on this list. Here is my evaluation:
1. I am split on this one. Units not dying after an attack is a nice feature, but it is a problem for Civ's with higher production. In previous Civ's the Civ with the higher production would normally win, rewarding that Civ for achieving a high production rate.
However in Civ5 I think this rule fits right in with the game. In other Civ's this feature wouldn't work. Its really just a necessity for tactical combat in Civ5 to have.
2. This feature is great. It is an improvement that I hope stays with the series.
3. I really don't care for leader animations. It has no direct affect on gameplay, but it adds a degree of immersion into the game. Leader animations will always be an improving graphical feature in Civ.
4. I think turn time is about the same. I have been using the same computer for Civ5 and Civ4. Civ5 requires a lot more RAM and Processor than Civ4, and I am at minimum requirement, but the reason why turns are still the same is partly to the lack of global trade routes. Global trade routes caused long turn times in Civ4 towards the end of the game, but they were still a really good feature in Civ4. Its probably better that their out of Civ5 since turns would probably last very long if they were left in.
5. I like ranged attack, but once again it is another feature to make tactical combat work. (I am not a fan of tactical combat). Without it tactical combat would be... not very tactical.
6. I like road matenince. I personally don't think it is a good feature to have in a 1UPT game, but if Civ5 had stacks it would be a great feature to have. Of course it does need some balancing.
7. This feature I also like, but GP also need a lot of improvement.
What I could add to this list is the idea of City states. So far City states are very shallow in my opinion, and could use a lot of improvement and change. For instance, a less obvious reason would be I don't think City States should be able to decide a diplomatic victory.
Thats just my opinion about everything.