I'm working 4 days 12 hours 4 days off, and it's a god send just for the mini vacation days off every week.
Yes the work days are long, yes it can vary from job, if it's a stressful job working 12 hours of it sounds like complete misery (Even though working one extra shorter day doesn't seem that much better, a stressful job is misery all the same) but it's just worth it.
I see some saying it's like 3.5 days off because the first day you spend it mostly resting from exhaustion, but normal weekends are basically 1 day off because again you're doing house chores, groceries, recuperating as well and before you know it's Monday again.
OF COURSE, I'd prefer 4 days 6-8 hour shifts for the same pay. That would be perfect