I tried the 24" which was rubbish (20% brightness difference from left to right) as was Dell's customer service. you will need a special $$ video card to run the 30" as most ordinary cards can't provide the required resolution.
The video card doesn't have to be that
special. All you need is a video card that has dual-link DVI and supports the resolution 2560x1600 at your desired refresh rate, there are now plenty of cards that do that.