Well, to be honest, if you are a big QOL kinda person, you should avoid International ACMI flying altogether.
What you have to understand is that if the Southern has a lot of work, you will be busy... Really busy. But if things happen to be quiet, you will sit in a hotel or at home a fair bit. There is no way to predict what your month will be like, until you are deep into it.
I have said it in the past, Southern is not for everyone. I'm not trying to scare people off, I just want to make it clear that it is better suited for pilots/PFE's that are able to adapt well to changing schedules...
In the not so distant future, when the B777's are on established runs, working for a specific customer, on a stable schedule... You might see a far better QOL, but that is our future ---> not the present day.
The best litmus test I can think of, to determine if Southern is for you is simple...
If after listening to a story about flying ol' Southern Air Transport Herc's around the wilds of Africa makes you say "Cool", then Southern might be your thing...
But if those same stories make you say "What the **** - Over", then I'd recommend you look elsewhere.
Just saying.