Hey all. I am in a dilemma about my next purchase. I need a new machine that is a must. I need a big 27" screen also a must. How does the iMac screen compare to the dell ultrasharp 27"? I know the iMac is LED backlit which is great but I also know the ultrasharp has 1 billion colours. New machine would have to be a PC unfortunately if I go with the dell screen as the mac mini will not be powerful enough and I can only afford just enough for an iMac.