The blacks with this monitor are phenomenal. It's LED backlit which allows for deep, crisp blacks right next to bright colors. Next to the S231HL, my other monitors and even my HDTV (which is admittedly a cheapo model) look HUGELY washed out, and blacks look terrible.
The size is also a nice upgrade, as I've been working off my once-secondary 13'' monitor since my old 19 incher's power supply ate itself. I have SO MUCH desktop real estate. I've been playing Capsized at 1920x1080 and it looks gorgeous. Definitely a very great monitor.
EDIT:
Just ordered a Radeon 6870 to go with it.
That'll be a nice step up from my GTX260.