[Upgrading, Modifying and Unlocking] OfficerJimLahey:
Finally got around to test. Looks great, I love having TWRP over CWM!

Unfortunately the backup function is not working. TWRP errors out and reloads itself. I have a pastebin, sorry it's so long but I wanted to try a couple different backup options before I gave up and produced a log file:

http://pastebin.com/QUfNw6Rk

The portions of interest are:

Backing up Cache...
I:Creating backup...
I:Creating tar file '/external_sd/TWRP/BACKUPS/1db9cba/1970-01-24--22-43-59 JZO54K//cache.ext4.win'
I:addFile '/cache/recovery' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/cache/recovery/log' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
...

Backing up Data...
I:Creating backup...
I:Creating tar file '/external_sd/TWRP/BACKUPS/1db9cba/1970-01-24--22-43-59 JZO54K//data.ext4.win'
I:addFile '/data/dontpanic' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg0' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/next_count' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg1' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg2' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg3' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg4' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg5' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg6' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
I:addFile '/data/dontpanic/last_kmsg7' including root: 0
Failed to get selinux context: Operation not supported on transport endpoint
__bionic_open_tzdata: couldn't find any tzdata when looking for localtime!
__bionic_open_tzdata: couldn't find any tzdata when looking for GMT!
__bionic_open_tzdata: couldn't find any tzdata when looking for posixrules!
Starting TWRP 2.7.1.0 on Sun Jan 25 03:44:01 1970
I:Single storage only.
I:No internal storage defined.
I:No storage defined, defaulting to /sdcard.
I:Lun file '/sys/devices/platform/usb_mass_storage/lun0/file' does not exist, USB storage mode disabled
I:Found brightness file at '/sys/class/leds/lcd-backlight/brightness'
I:TWFunc::Set_Brightness: Setting brightness control to 255
Starting the UI...Pixel format: 480x800 @ 32bpp
Pixel format: RGBX_8888
Not using qualcomm overlay, 'msmfb43_80201'
framebuffer: fd 4 (480 x 800)
=> Linking mtab
=> Processing recovery.fstab
I:Processing '/boot'
I:Processing '/cache'
I:Processing '/data'
I:Processing '/misc'
I:Processing '/recovery'
I:Processing '/external_sd'
I:Processing '/system'
I:Creating Android Secure: /external_sd/.android_secure
I:Backup folder set to '/external_sd/TWRP/BACKUPS/1db9cba'
I:Settings storage is '/external_sd'
Updating partition details...
I:Unmounting main partitions...
E:Unable to unmount '/data'

I have a stock based ROM to test, and I want to make sure I can enter recovery through the bootloader should things go sour. If TWRP can backup and restore, that allows me to go back to my true stock after the test. Any ideas?