I played a Kings of War game and then a 9th Age game today. Using same armies across both systems. Beast Herd for Mike, and Nature/Sylvan for me.
We used very similar army lists in both games. Most units seemed to function in a similar way, except that Thicket Beasts/Forest Shamblers seem considerably tougher in 9th compared to Kings of War!
KOW took 1.5 hours, 9th age 3 hours.
Both had clear victor turn 4. Commentary for both games in captions for photos.
Kings of War
Kings of War for first game. Invade Scenario. My Eagles swing around both flanks, one dies to Harpies and flank charge, other kills off wounded Trappers (Mongrels).
Thicket Beasts (KOW Forest Shamblers) are powerful in 9th and take down an entire Warrior Herd over 3 turns!
Minotaurs flanked and routed but manage to run away.
But Herd units in centre all broken or about to be. Sylvan (Nature) have only lost half a Dryad unit and a Thicket Beast, plus a few wounds on Treeherders and a Druid. Game called for Sylvan turn 4.