So, I went ahead and bought the 13" rMBP upon it's introduction last October, selling my mid-2010 27" iMac in the process. The iMac had a 2.8 GHz QUAD-core i5, 4GB of RAM, and a 1TB HDD. And of course, my base 13" rMBP has a 2.5 GHz DUAL-core i5, 8GB of RAM, and the 128GB SSD. While the 8GB of RAM and SSD are upgrades, I think I finally noticed the processor downgrade when encoding a movie in iMovie last night. My question is whether or not a 2010 quad-core i5 chip is THAT much more powerful than the dual-core i5 in my rMBP to the point where the time difference of encoding a video would be significantly noticeable? Thoughts?