I've done speed tests on the last few MacBook Pro models from 2013, 2015 vs. the new MacBook Pro (Late 2016) models in 13 and 15 inch.
For us who are looking for the fastest possible workflow of processing pictures in Lightroom, the new top-of-the-line 15" with 2TB and maximum RAM, processor and graphics card is beaten by the previous model. The latest of the old MacBook Pro 15" is 14% faster than the current MacBook.
I've posted the tests here of the different computers, as well as a writeup on USB-C vs. Thunderbolt 3 hard drives, and more.
A complete workflow of import, building previews and exporting files is 16:54 minutes on the previous model and 19:36 mins on the new.
http://www.overgaard.dk/the-story-behind-that-picture-0169-Advice-for-Photographers-Which-Computer-for-Editing-Photographs.html