i downloaded it this afternoon and playd a couple of matches with it, i really liked the upgraded mercs from the get go , makes them distinct and usefull , exactly what should set them apart from citizens . Cavalry having a buff to their health is nice although i would see certain spear cav having their damage increased such as the companions for makedon but maybe it would make more sense to buff the spear cav of civs that don't have any other melee cav as the sucessor states to make their cav a bit more all rounder . As for the counters , well age of myhtolofy seemed to it pretty wel especially with the greek ones wich i have put the link bellow :
http://aom.heavengames.com/cgi-bin/forums/display.cgi?action=ct&f=11,16332,0,all