UPDATE: Yeah, nandroid backups are broken on the 2/13/2017 build, as well as magisk installation. I saw a developer describe this as an issue with the data partition being locked down while you're in TWRP. So DO NOT rely on a NANDROID backup on the 13 build or any later builds until new TWRPs are released.
I'm on the "best" one so far, codeworx, and I get error 255 when trying to restore data.
You can still backup system, system image, efs, etc. Those all work. But as soon as you start restoring data, I assure you the backup will fail.
nandroid currently working: 2/09/2017 build
nandroid data restore failure: 2/13/2017
TWRP status: I have no idea, are there new releases of TWRP that fix this problem?
Appreciate any input guys.