Doh, major mistake on my part. I'll post what I did as a warning.
New SGS4 set up how I wanted rooted, Philz CWM successfully installed, Busy Box installed, first Nandroid done, efs backup done, titanium backup done.
Right down loaded this 3minit framework :
Correct for my firmware (I9505XXUBMEA) you might think, Nope I'm still running stock Vodafone odexed ROM.
Flashed it and it seriously borked my phone. It booted but was in that stupid 'easy' mode, which FCed almost instantly on every boot.
I think my odexed ROM caused it. It has to be. Thank heavens for Nandroid.