I got a new MacBook Pro on Monday: a 13" Retina with 16GB RAM and 500GB SSD, which doubles both the RAM and the disk capacity of its late-2013 predecessor. 8GB wasn’t really enough for software development. By the time you run Chrome and PyCharm and Docker, you don’t have much RAM left. And I was constantly having to run Grand Perspective to clean up disk space.
For the first time, I used the Migration Assistant and a Thunderbolt cable to transfer settings from the old laptop to the new. I was pleasantly surprised at how well it worked. In one hour, the new machine had all the files and just about all the settings. I did have to swap the Cmd and Option keys on my external keyboard and reconfigure the Display settings for the external monitor, but that’s about it. I also had to update to OS X 10.11.4, which I had previously done on the old laptop.