Gives you a sense of scale and excitment in battles most other strategy games can only dream of.
The gameplay has been improved since the last one, Medieval: Total War. Units are easier to select and the interface is slightly more user friendly. Organizing your troops in the heat of the battle is much easier, and the ability to see which enemy is routing is a plus as well.
Sieges had a great facelift. No longer are sieges only castles in the middle of no where. There are huge cities with hundreds of buildings and winding streets which adds a lot of strategic aspects to the attacker and defender.