I use my laptop almost exclusively to process my D800E files in both LR 5 and PS CS6. I also use it for light internet browsing, but I usually use my iPad Mini and iPhone. Currently I have a 13" rMBP 2.5GHz with 128GB flash storage and 8GB of RAM. I'm looking at the 15" rMBP with 16GB of RAM and 256 flash storage. More RAM will obviously help with processing the D800E RAW files, but the bigger screen real estate would help me out when I'm using LR and PS. Portability really isn't an issue since I really only take my rMBP in different rooms in the house. I don't process on the go or anything like that. B&H is running a pretty good deal on the 15" currently, so I'm thinking about pulling the trigger real soon. For those of you who primarily use LR and PS for photo editing, is it worth it to go from the 13" to the 15"?