Well I took my iMac in for freezing a few weeks ago (before there was an update). My old mac was a week 34 my new mac is a week 46. 1. I would like to say that the freezing is now completely gone and I did not have to install an update. 2. My old screen was kinda yellow on the right side. (The yellowing gradient problem). My new iMac is Perfect! the screen looks awesome! 3. My new mac mac came with what looked like 3 dead pixels. I took the class off with a little suction cup, and there was dust on the lcd panel under the glass... I wiped the dust off, and now I have a perfect iMac!