It also depends if LCD color shifting bothers you when viewing at an angle. I don't need a 24" and gaming will probably suffer from the higher native resolution (although my previous 20" display quickly grew too small for me..), but I can't stand the viewing angle on the 20". To me, the viewing angle and higher resolution is worth the money.
Someone convince me otherwise. 🙂 I really want to open the one sitting on my desk, waiting to be returned.