I agree. With 500 pictures a day and you like to work the whole bulk in a single session, you should get the rMBP 2015, especially if it is your only computer. Personally I may shoot 200-300 a day, but I no longer save all my pictures. I preview them in Finder and quick look, pick out the dusin I want and do edits on them. I usually know which shots are interesting from the lot before I import.
Wedding photographers or photos for industrial/professional documentation, in regards to insurance and policies, may need to save every shot they have. Going through a month long project in some nature setting may also need the power to go through the vast amount of photos. Now that I use a Macbook, I can bring my computer everywhere and check the pictures on the go. Before I would always wait until the end of the day, process the lot in bulk and use management software like Lightroom or Aperture.
My workflow have changed from saving massive archives of photos to hard drives (which would usually just stay on the HD taking space), to sorting out shots I care about and saving them to the cloud. During a month I may regret loosing a picture or two with this process, but I believe less is more, both in management and in actual selection. A study comparing people who had the opportunity to change their first pick over people who had to stick with their original selection, showed that the group who had only one opportunity to choose which picture they wanted, was the most satisfied photographers.
If you are in need of an ethernet port for your tasks, you may as well buy a dock, for it means you are not going to move your computer around much. I had one, and it served me well, getting monitors, USB devices and ethernet connected to my rMBP with a single cable. I really like the digital Multiport adapter I use with my Macbook. It may be limited to 1920x1200 at the moment, but I believe it will change with Thunderbolt 3 on the new Pro design giving it support for 5K over SST.
As much as I love raw power, I would rather have a retina Macbook Air with a quad core CPU than the bulky design of the current MacBook Pro. Kill the dGPU in the new design, but leave a classic choice for the boys who need something beefier than the integrated graphics. Change the dGPU option to a GTX 965M with CUDA support. AMD is only alive thanks to the next gen consoles, and have totally lacked any leadership in the computer scene.