I don't have any scientific way to test the results so this is all observation. Note I am upgrading from an old 15" ibm flat panel so the differential is large.
I got my new 23" on tuesday and due to the fact that my G5 isn't shipping yet I hooked it up to my Windows box. I have to say the color, clarity and brightness is amazing. (I had to turn down the brightness.) I am not sure if it is attributed to the widescreen aspect or the resolution or the quality (likely all three), but the feeling i get was in line with the first time i watched an american football game in HD (seeing the grass, feeling like you were actually there). (I've got a wallpaper pic of the colleseum up right now and it looks like I'm looking at the real thing.)
For viewing angle, anywhere i look at the monitor from its the same. It almost makes it look like a poster on the display (thats how uniform the viewing angle is).
So far I've played UT2004 and Neverwinter (note again I'm on a Windows machine until my G5 arrives) and it looked good. I wasn't upgrading from a CRT so I can't compare there, but there was no blurring, etc.
Watching a DVD via windows media player was also good.
Overall I am very very impressed and pleased with the purchase. I can't imagine what it would be like with the 30". Probably unreal.
-jim