I have one of the original Apple Flat Panel Studio Displays (15") and lemme tell you, I can stand to watch DVDs on anything else!
The quality is purely amazing. In well mastered DVDs such as The Matrix, when there's a closeup of someone's face, you can count the pores on their face! It's that good!
Just make sure you watch DVDs that are the widescreen format. I've seen a few DVDs that were taken directly from VHS and they suck arse! Plus you see the movie they the cinematographer intended you to view it.
Hope that helps! Later!