Has anyone purchased the Thunderbolt Display and used it straight out of the box with no calibration needed. If not, what was the reason for the calibration, cool blue hue, uneven colours/tones, bleed of colours ?? Those that have calibrated please could you share info on what tool you used and how long it takes to calibrate please as this would all be very new to me?? Have had a bad experience with first one and returned it for my money back due to blue tint to the left of the screen and the "whites" were by no means "white". Do I try another and buy a specific calibration tool ??