I've been playing with ACE 1.10 recently, and i have to say fighting the AI is quite enjoyable now. They are doing some really impressive stuff if you consider it's an open world AI with no scripting going on to tell them what to do.
Last night i only placed a KCT Commando-group in the editor on the Fallujah map (large city-map with over 3000+ buildings, based on sat-images) and put myself as the squad leader, and all i did was add the SecOps-manager.
Well, it wasn't long before i was ordered a mission and later on a second, to perform a patrol through some checkpoints randomly generated within the city. From the first mission i had gained a reward, with which i was able to call in an Apache for fire support.
As i went on my merry way we entered a relatively open area with some buildings spread here and there. Ofcourse it wasn't long before enemy soldiers opened fire from about 5 o'clock.
I hurridly took cover, making their location my new 12 o'clock. Around me, my AI soldiers took cover on the wall, while those at the edges leaned around the corner and provided suppressive fire.
About a minute in the firefight, i still hadnt spotted the shooters which were hiding in some rubble which i later found out, as bullets cracked overhead.
And then the worst thing that could happen, happened: shots came from my new 6 o'clock, effectively sandwhiching me and my squad between two enemy patrols, leaving one side completely open and without cover.
I quickly turned around and fired in the new direction i had to face, supported by two soldiers, while the rest were still searching our 12.
Then i noticed a muzzleflash: the newly arrived enemy soldiers were using columns of buildings for cover, leaning around, firing, and sidestepping from cover to cover!
After me and my squad killed several, i decided to use the lull in the fight to move to new cover, and i ran over to another building and went on to sit on the roof, hoping it would give me a good view of the soldiers on my 12, while keeping out of sight of the soldiers on our 6. Ofcourse, that put me in full view of some enemy soldiers, and i got hit in the arms, messing up my aim considerably. Still managed to hit a soldier or two, but the situation was getting hopeless.
So, time to call in that Apache support!
After contacting HQ, i gave a location for the Apache to search and destroy. It took it's sweet time getting to me though, and all the while i was taking rounds from the front and the rear.
When it arrived it took a quick pass or two over the area (i guess it was determining friends from foes, or simply detecting foes

) and as i grudgingly thought to myself "Bloody useless Apache!" it came around for a third flyby and what followed then was simply hell for the receiving side.
It opened up with it's boardcannon and insurgents were falling left and right, i even saw one of them take a dive through the air

After that succesfull strafe, it suddenly went quiet. Area cleared

Completing the patrol was easy after that.
The AI was continually impressing me during the fights i had to fight.
They took cover at corners to lean around them, used trees, traffic lights, individual slabs of concrete of a watertower, piles of garbage, building columns, carwrecks and all other kinds of crap for cover, and all but one of my squad managed to stay alive through at least a 15 minute firefight with fire coming in from two sides, and the enemy forces did at least as good a job. It certainly took me my sweet time to determine where they were firing from
