I have worked these before, and my family has tried these. My mum is a nurse, so she frequently worked 13-hour days 3 days a week when I grew up. My dad worked in IT for a long time, by the end he worked exclusively these shifts before he retired to start his own business.
I agree it's ultimately harder, especially with younger children, on those days that you'll work harder. It will inevitably be a personal choice whether seeing them a bit every night is more important than seeing them a lot on one night.
All I can say is from personal experience as a child with a parent who worked those shifts (I haven't got kids yet, so I can't speak from the parental perspective). My dad regularly worked those shifts, and when I was younger it was certainly tough (its a little different in your teen years when you're up later and more independent), but the fridays he got off were always worth it. I remember getting off school and we actually had the time to go to a theme park on my birthday (I believe he switched his shifts to get a tuesday off) or that we'd get to go to the movies or bowling before they got packed on a friday evening.
I can't say not having your dad there wouldn't be hard on a kid (in the last few years, and the reason why he left the job, he had to work away from home so then the 4 day week really helped as he wasn't home for 3 nights instead of 4 nights), but from my own experience the quality time certainly made up for it and in hindsight I think I actually preferred when he had the 4 day weeks.
Perhaps it would be more of a win-win when they're in high school rather than junior school as with the amount of homework that gets dumped on the teens, they'll barely notice if you're an hour or two later home.
I suppose it all depends on you as the parent, your spouse/partner and your kids. 5 days may be best for you, 4 days may be better for others, but a trial-run for a month might give you a clue as to which you and your family prefer.