medieval sucks because too many crazy characters in the campaign map, secondly and most importantly in battles, the units for example, guns really destroy the game, theres no skill in having 10 units of gunmen etc, its totally annoying mixed in with normal troops.
the chavalry charges dont work well, the engine i think for rome is better, they move faster and hit better. in MED 2 you have to line them up forever, and even then sometimes it doesnt work
Imperator 2 is very good
http://www.twcenter.net/forums/showthread.php?t=54640&page=1
its very very hard, the AI is smarter and there are 22 types of legionnarie available, EG Legio I Italica - Recruited from among the citizens all over Italy
* Legio II Augusta - Recruited from the former Carthaginian province
read the link for more info + download links ( you must have barbarian invasion installed)
EDIT: here i have uploaded 3 screenshots of imperator
http://www.xfire.com/profile/bprelec , on my Xfire profile, feel free to add me and talk about it