im playing it on "Realistic" difficulty, but enemies seem incapable of seeing more than 10 feet in front of them. i can be right in front of them, walking towards them while shooting repeatedly at them with an unsilenced pistol, and they are completely oblivious until they get hit or i come within their tiny little sight range. if i get shot in the head it is pretty lethal, but since the enemy almost never shoots thats virtually a non-factor.

and whats the point of moving bodies if the brain damaged AI is incapable of noticing them?

snipers seem to be able to see an acceptable distance but they are extremely rare, and since everyone is deaf theres no reason not to just blow them up with heavy weapons. are there any mods that make the AI less terrible? or is "Realistic" difficulty broken, maybe?

Deus Ex Hardcore mod from moddb.com KICKS ASS :D

I don't know anything about this hardcore mod but I'm very happy with G-Flex's Human Renovation mod because it does make the AI a bit quicker to respond without making the core gameplay of sneaking past them tedious, ie it doesn't break the core design while still upping the difficulty.

the only difference i notice with the hardcore mod is that enemies can see and hear a bit further, and if they lose sight of you they mill around for a few seconds instead of instantly announcing that you must be gone.

for instance, in the first mission, if you start shooting at the terrorists from the ramp leading up from the dock where you start out, that will result in like 6 guys converging on you, instead of the one guy you hit running over and everyone else continuing to walk back and forth.