Hi Guys New to the forum here. I am after some help regarding the new MBP's. I currently have a late 2013 iMAC with the GTX 780M with 4GB as well as the 12 inch Macbook. My goal is to end up with one computer which can do it all. Now I am assuming here the graphics cards in the 13 inch version wont cut it for 4k video editing? or will they? I am looking to get similar performance as I would get off my iMac for the video editing. Aside from that I do a far bit of photo editing in lightroom and photoshop. I travel a lot so the 13 inch would be preferred but the if the graphics cant cut it which 15 inch do I need? Thanks for your time.