the ignoramus
Regular
Most of the time the cleverness of the AI is not going to become greater with increased difficulty, the usual path for most developers is to "cheat", making the enemy AI more accurate, powerful or stronger, instead of actually making the AI smarter.
End result is a harder game with both approaches but latter one is atleast to me the most appealing but sadly much more expensive.
Lets hope KZ2 is one of the titles where cleverness is increased .
I asked Seb Downey, GG's QA guy, how they adjusted the AI at different levels of difficulty and he said that the AI just took more damage. (and the player took less)
However, I've heard reports from other folks that contradict Downey's statement.
Those that have played on veteran claim that the AI reacts to situations more quickly and throws grenades more often.
I would imagine the AI shines on Veteran and Elite, not because the HGHs get "more clever" but because you advance more slowly and leave yourself open to a greater variety of attacks patterns.