Hi I've decided that the 2016 15" is the right model for me. Most of the time it'll be connected to an LG 5k too. The only problem now, is which model. Daily Lightroom and occasional Photoshop use with RAW files will be the most intensive work I do. Fairly basic stuff mind you. Not stitching together huge panoramas or anything on that level. No video editing at all. So with this in mind, I'm thinking of the base model with a 1TB SSD. But when it comes to graphics I'm not sure what to do. Would upgrading to the 460 be worth it, or would the standard 450 do me just fine? Thanks!
For pushing the huge amount of pixels of the 5K I'd go with the 460. It's relatively cheap compared to what you get (+80% TFLOPS). I get some stutter here and there with the 450 connected to a 4k display, so you'll need all the GPU power you can get. I'll be returning my 450 as I have a 460 on its way (delivery date in two weeks).
I think at the (relatively) low $200 cost upgrade it's a no brainer for the 460. It's much faster and if you do ANY 3D gaming at all you are going to be glad you got it.