I work a 9/80 schedule right now. It's really good because:
1) You can schedule your vacations to coincide with your 9/80 Friday, so you don't need to take a vacation day that day.
2) You can schedule all sorts of doctor/dentist appointments for that day.
3) Gives you a day to catch up on doing stuff around the house.
4) It's super flexible, at least at my company. If I need to take a day off during the week for some reason I can just make it up on the 9/80 Friday I would usually have off. Or if I need to leave early for a few days out of the week, I can just come in on that Friday and make up the time.
5) I have never been pulled into work on that Friday, unless it was by my own decision.
6) On the Fridays that are not 9/80, it's exciting because you can leave an hour early!
7) I still have time to do whatever. Yesterday I went to the gym and out to dinner.