I never played medieval so I dunno if I can compare them, but I can try to rebuke some of your points about the RTW campaign map:

-Management increases tax income. I hardly comsider that a marginal and temporary effect, epsecially in big cities.
-Moving armies around without action. This is becuase of the movement system, IE armies going actual places, not just province to province like in medieval. In other words, in medieval you could get a field battle even if the your amry was at one end of the province and the enemy at the other. The movement system now is more realistic and fun (although, not that realistic, as simmetrical pointed out)
-Ships take ages. This is a very good thing. it discourages you from loading up an army, running into greece, Sacking Athens for like a billion denarri, and running back to your homeland all in one turn like you could in medieval (from what I hear)
-Total war is about diplomacy. If it wasnt they would have just made it all custom battle and not even bothereed with a campaign map. It is about, economics, management, diplomacy, etc.

In conclusion, The RTW campaign map owns. Dunno if medieval was better, but RTW is great.