Hi guys, i had some questions about the 21.5" Low end and high end iMac 1. Can i use it as a display, i heard something about the 27" It would be great that i can use 21.5" gorgeous display with my PC workstation, since i can't really use a 24" LED ACD 2. Did the 21.5" ones have Yellow screens too? 3. How much better is the ATI vs. the 9400M, is the ATI one replaceable in case of failure (already suffered a lot with another iMac which had a Graphics card failure which required a Logic board replacement) 4. What's the quality in compared to the LED Cinema Display? 5. Is it worth it to get the 3.33GHz Processor? EDIT: 6. If i have a 1TB HD what would be the best size for a time machine external HD?