I am looking to purchase a 15" MacBook Pro Retina, I am trying to decide if the upgraded model with the 2gb dedicated graphics card is worth the price for what I will use it for which is mainly photo editing using Lightroom CC mainly with the occasionally going over to photoshop. I don't do video editing except for some timelapse. Should I just get the base model with 16gb of ram and the 256 ssd? My main computer is a 27" iMac, this one will be mainly for travel and on the go editing. I plan on using a 1 or 2tb external thunderbolt drive for storage

