2048x1280 (switchresx)
I am a photographer and a photo retoucher as a day and night job.
I use Final Cut Pro, Lightroom and Photoshop heavily. I use my built in display primarily when shooting on location. (Which i am most of the time)
i find all of the retina resolutions giving a hit on performance thoroughly while doing processing work with my machine. The "best for retina option" may be the suitable "okay" performance for my workflow but the screen real estate is just lacking.
2880x1800 is a headache when viewing (IMO).
Below the 2048x1280 resolutions on non Hi-DPi, fonts tend to be blurry, even viewing photos tend to give a bit of a blur which is a big no in our work.
So after using the workflow resolution, i switch back to retina resolutions for proofing. Until osx gives a better performance / optimization in retina resolution i'll stick with these resolutions