For me it was a great balance: instead of the weekend feeling like days off from work, general life felt like alternating between holidays and work, since they'

For me it was a great balance: instead of the weekend feeling like days off from work, general life felt like alternating between holidays and work, since they're about the same length. 3 work days might work as well, but fewer than that and you start to lose the flow at work. And given that I do generally enjoy my work, it isn't necessary for that holiday feel anyway.