So to start, I was having a real problem getting SP to work properly no matter how carefully I followed instructions.
My Arma clients are on Steam, installed on a G: drive and I use Commander to run it.
My fix was to uninstall the separate Beta patch marked obsolete in Steam and make a backup copy of the @DayZ folder. I pasted the DayZ X addons over the original addons in the @DayZ folder, moved the updated mission files as usual and hit Launch in Commander.
Basically I'm using the @DayZ "label" to launch all different mods. If I want to change mods I just assign the @DayZ name to whatever folder.
I'm not sure where the problem was and this works for me, hope it helps someone o/
P.S the new map is awesome! Enabled Super AI, Cherno was a massive fire fight :)