Just to share my experience, not sure if someone posted the same thing before.
I have Z ultra GPE from Expansys-USA. Updated to 4.4.4 yesterday then wanted to root it.
First I tried " Easy Root Tool for various Xperia devices" http://forum.xda-developers.com/show....php?t=2784900
but didn't work.
Then followed "Towelroot: One-click root" http://forum.xda-developers.com/show....php?t=2783982
"- Go to http://towelroot.com/
- Install APK
- Run APK
I tried different modstrings then this one ""1337 0 0 0 6 0" worked.
Verified with Root Checker.
Then TA backup.
Then installed Super SU, and started to use Lucky Patcher to remove google ads from some apps