I just got a 23" ACD and for the most part, it's awesome. The color and uniform brightness have made me hate my 17" MBP hi-res screen. I thought the MBP had a good display until I started using this thing! Anyway, I have a slight problem with the ACD. It has no dead pixels or anything, and is perfect except for a horizontal line that runs from end to end, dead center on the display. It is not clearly defined and sort of blurry, and is most visible on blues and grays and especially on solid colors. It's one of those things that you may not see unless you are looking for it or know it's there. My question is, based on others' experiences, whether I should take it into the Apple store and ask for a replacement or not press my luck and stick with the one I have.