Sciolistes,
I have no idea for who you are flying since you left FZ but I can tell you that with my experience of low cost in europe ( Ryanair ) and FZ here , I still prefer Ryanair...
Why ?
You can really enjoy flying manually there and they have some nice and challenging approaches to play with including visuals or circling.
The roster was a lot more stable with no night flights ( 5 days flying always followed by 4 days off ; 5 days early departure 4 days off then 5 days afternoon departure 4 days off etc...)
If you make a mistake , you will be grounded , sent back to the simulator for some specific training then back on line )
Here you get " fired " or should I say they ask you to resign...
So I am not really sure why you regret FZ and talking about fatigue , I have never been fatigued at Ryanair because I had always 4 days off to recover and never shifting from day to deep night and vice versa...
FZ is definitely a lot worse except for the money