I opted for monday off when i worked 4 days a week, i tried wednesdays a few times but didn't like it as much

I preferred the large block of time off, I found that I enjoyed Friday-Sunday more knowing I had a bonus day on Monday to relax - I could really pack in stuff over the weekend without worrying about being exhausted back at work. And I found the Wednesday off just felt... wasted. Nobody else was free, nobody really wants to do things on Wednesday, and I wasn't tired enough to want a day of doing nothing.