I worked “4 on 4 off” for a solid six years. Sure you only work for 50% of the year, but the constant weekend work (4 weekends out of 8 you’d be doing at least one weekend workday) grinds you down, plus the fact that it was one flat rate of pay regardless of whether you were working Monday to Thursday or the entire Friday to Monday Easter Weekend, which of course encompasses two bank holidays. Also I never got any extra holidays, just the company’s standard 20 days per year.