Hello, people I'm a new guy here :).
First off I'd like to commend your post for at least backing up your claims. And I agree with you that KZ2 shines because of its art design, including its monochrome aesthetics. But in my opinion what makes it stand out are the animations. The game has really smooth animations. As a level designer I find KZ2 to be very bland in level design, it reminds me of level design from PS2 games to be honest. I am not saying that the game sucks, I've played it and it is a fun shooter in its simplistic form, but nothing revolutionary as a lot of people claim it is.
On the other hand I have only played a snippet of GOW2, but I own GoW1 on PC.
But this topic is not about level design , it is about art direction and technology. So the topic at hand is UE3 vs KZ2 engine(I cant find the name of KZ2's engine.) GoW and KZ are very similar in art design, destroyed industrial areas, destroyed city areas, clausterphobic interior corridors, and shades of grey to be general. However I think KZ2 has more in common with GOW1 than GOW2 as far as color pallette. Epic extended their color pallete for GOW2 and it is a great improvement over GOW1.
With all of that said any graphics / game engine comparisons are misguided when they do not include the current top contenders including Crysis, Crysis Warhead, Call of Juarez, STALKER CS, Gran Turismo 5, and Mirrors Edge when it comes to graphical comparisons.
Specific game vs spefic game is pretty limited.
