I bought a new MacBook Pro.
Nine times out of ten if I buy a piece of hardware it's a response to stress, I find setting new hardware up to be relaxing, it helps distract me. When my father was dying I went through a very large number of laptops. It's an expensive habit, but I don't drink or smoke and rarely buy anime any more.
(At this point I should point out the old adage "Anime, drugs would be cheaper" - I don't have a clue how much drugs cost, but I know how much I used to spend on anime. It was a lot.)
So, I decided to get a new Retina MacBook Pro with a 1TB SSD. But for once I didn't want to do a setup from scratch, I'd just sync'd a couple of hundred gigs out of the cloud and didn't want to do that again, even over fibre. So I bought a Thunderbolt cable to do the migration from my old Mac.
It worked very well, but here's the things that happened.
Remember first of all to turn off FileVault on the old Mac. I did this before I started. That meant I could use Target Disk Mode.
I didn't read the instructions from Apple, so the first migration I tried in Target Disk Mode, the connect glitched after 20% of the copy or so and the new Mac thought it was done and booted. Almost nothing was copied. I didn't think of restarting Migration Assistant, I just used Recovery to reinstall OSX and go again.
Second time I tried not using the old Mac in Target Disk mode, which was what Apple advised, it looked like it should work, but when it came time to copy it couldn't see my Home folder and thought there were no files to copy.
So I restarted the old Mac in Target Disk mode again, and this time it worked. Once it booted I had to reconnect Google Drive, reauthorise Dropbox, put back in passwords for iCloud and the App Store and then it was good go. My Backblaze backup picked up seamlessly. I renamed my main disk to the same as my old Mac then told it to do a Time Machine backup too. It had to deep scan my old backup then said it had 310 gigs to backup. I woke up 7 hours later to find that whatever it had done it had worked out it didn't need to copy all those files again. I verified the backup, then checked it still had my old data in Time Machine. It does.
So, I cautiously recommend a Thunderbolt Migration. The first one failed, and Apple's instructions didn't work, but when I used Target Disk mode and the connection didn't glitch it was very fast, and all my old data is over - it's just like my old machine got much larger and slightly faster.