I'm using 2012 non-Retina MacBook Pro - i5, 8gb ram and SSD drive. In overall I'm quite satisfied with how it performs, but when I play with RAW files in LR and export them Macbook starts to show it's age. It runs much slower and temperatures are going high quite fast. I'm not interested in new Macbooks, but I would be more into MacBook Pro 2015 with i5, 8/16gb ram and SSD. But - would such change result in increased performance and overall better experience ? Would this be a game changer and Macbook would be much snappier or would I simply feel some difference, but not that significant ? Is it worth in general to shift from 2012 to 2015 Macbook ?