I'm looking to buy an iMac since my macbook pro is starting to crap out (it's 4 years old) and can no longer use Final Cut Pro without the pinwheel popping up every 15 seconds or so. I'm looking to get a 21.5", but don't really know the difference between the i5 and i7 quad cores. I was looking at an i7 2.8GHz core, but was thinking about upgrading it to a 3.6GHz. Is that a good idea or would I just be wasting my money and a 2.8 would be fine for video editing? I work with Final Cut Pro, Compressor, After Effects, and sometimes Photoshop.