I have a late 2007 iMac and its on its last legs, so I think it's time to upgrade. I'm wondering performance wise which model is best? A MacBook pro 15-inch: 2.5GHz entry model or the iMac retina entry model? The computer would be used for graphic design photo editing etc. I'm look for something that can last me another 7 years so I need something that's good performance wise and not just a pretty screen. Any help is appreciated, thanks.