Let me also just advise you to stay far, far away from any TN panel at any cost. I figured I'd just get the 22" UltraSharp at first, had to send it back because it's just not good enough for writing code.
Second on the TN type panels. Buy a panel type, not a manufacturer. Some shoddy ones like "AOC" or even Visio may use different (whatevers cheaper) panels over time and sell them as the same model number. I've got 2 AOC's I bought about 6 months apart. Both exactly the same model, one is great, one terrible.
Here's some good info: http://www.pchardwarehelp.com/guides/lcd-panel-types.php