Really superb! But...
The great problem in my opinion is the battle engine. I really enjoy battles like the Age of Wonders II system. I still play that one, believe you or not. In Civ IV you don't have control of the units in battle and only attack 1 at a time thus having a huge stack of units means almost nothing against a medium sized city garrison... you'll probably ending losing 1 or 2 of your veterans to take some defenders. Needless to say I hate "autobattle" systems!
The fact is that if the Civ IV battle system was similar to the AOW II I would give it a 10 score!
That said, it still a 9 score game that's worth playing for a long time!