After a lot of thought I managed to purchase a title model 15" 2012 Retina with 16gb ram 768 GB drive and the nvidia 650m brand new still sealed (I know 😱). After pricing up an Air using my educational discount with i7 256gb 13" this was effectively £300 more. I couldn't justify the extra £600 which would have been more than £900 over my original budget for the latest 15-inch: 2.3GHz with Retina display. The reason why I was looking at the air was next year I would be upgrading and this would be passed on to her replacing her MacBook Pro 13" i5 2011. So now she will be getting a lot better machine which will hopefully last longer. My question sorry to tell a story here is the model I got better than the current base model 15-inch: 2.0GHz?