I'm about to pull the trigger on a Late 2012 iMac 27". I was pretty much set on the 3.4Ghz i7, but now I'm wondering if it's worth the extra $200 for me. I'm a photo retoucher.....mostly Photoshop CS6, plus processing images with Capture One Pro or Lightroom 4. I also do some video encoding with HandBrake. If I'm not going to notice an appreciable difference, then I might as well save the $200. My thinking with the i7 is that I'm also future-proofing my system....perhaps it will last me longer with the faster processor. Any thoughts?