Hi guys and thank you so much for the valuable information on this forum. I've researched a lot but still have some questions that I need your expert feedback on. I was wondering if any of you who have managed to upgrade the i5 2.7 CPU to the i7 2600 CPU in the 27" iMacs have ever had problems. I would be interested to know the following: 1. how long have you used the machine for with the upgrade? 2. are you using CPU intensive software light lightroom / media encoder / photoshop or high res games? 3. has the system been as stable as before until now? 4. has the mac been noisier or much more hot? 5. do you happen to know if the PSU and cooling components in the the i5 and I7 iMacs as sold by Apple are the same? Thanks a ton.