Does the 2014 13inch vs 15inch Macbook Pro Make A Difference?

I'm currently a Design Comms student and I'm thinking of changing my 2012 macbook pro to the new 2014 retina macbook pro. I'm torn between the choice of the 13inch high end model of it's kind or the 15inch low end model (The one without the graphics card.). Which one should I get? And will it make a big difference?