You guys hit on visual clarity a lot, but some of the things you said have me scratching my head wondering if you actually understand what is meant by that artistically in this scenario. It sounds like you do when you state that it is hard to pick out players in UT3, and that would be the end result of a lack of visual clarity, but the level of detail has little to do with it and you harp on that a lot.
So what am I on about?...
Fig. A:
[SCREENSHOT]http://i.imgur.com/2pHXgkF.jpg[/SCREENSHOT]
Fig. B:
[SCREENSHOT]http://i.imgur.com/CFvcnCz.jpg[/SCREENSHOT]
Fig.A is clearly concept art for Deck. Specifically UT3 Deck. Fig. B is the execution of that concept. Both exhibit hi levels of detail, yet the visual clarity of the concept is 100x that of the execution. (I like the hyperbole, I am gonna role with it.) Clearly it is not the level of detail at fault. Nor in fact is it the post processing as there is little to none visible in the SS. What is visible and I would think apparent to everyone is how washed out Fig. B is. The tones are so muted as to be almost monochromatic. There is both lighting and color contrast in Fig. A the halls are lit in blue and the ooze is toxic glowing green While light streams in from above. This results in a scene that is both pleasing to the eye and easy to visually navigate. Fig. B is dead it's lifeless picking out the individual elements is a visual chore. The fact that there are 2 players in this scene and the gore from 1 that was just gibbed is extremely easy to miss. If I didn't know what a link gun looked like and was viewing this SS I might think that it was a ugly odd lamp.
Now for shits-n-giggles Fig. C:
[SCREENSHOT]http://i.imgur.com/zUIMGB5.jpg[/SCREENSHOT]
All I did here was paint a little color onto the original SS and it made a hell of a difference. Same amount of detail.
Not that I am against a cleaner look. Bonescraper is a decent example of that and perhaps that is why you used it... but it also has more vivid lighting.
Crisp edges on things do help but only moderately. I really boils down to the characters not blending into the background and/or everything turning into one nondescript blur when playing.