I assume you video card is an ATI with both an ADC and a DVI connector. If this is true you have many options.
The numer one reason to go with the Cinema Display is that is has an ADC connector and will look great next to you tower. But, if you want a great screen, you can get a new HD with better resolution, faster response time, higher contrast, and greater luminance. Check out Samsung, Viewsonic, Dell, or Gateway. You have a plethora of options.
The old Cinema Display was high end in it time, and it does have true colors. Still, LCD's are getting cheaper and better every day. And, if you ever choose to replace your tower, that ADC port with be a liability, since you will have to get a $100 adapter to get to work with DVI.