Is a 9/80 work schedule a good thing?

cellocgw writes: "My company is in the process of implementing a version of "9/80," a work schedule which squeezes 80 hours' labor time into 9 business days and provides every other Friday off. I was wondering how this has been implemented in other companies, and how it's worked out for other Slashdot readers. Is your system flexible? Do you find time to get personal stuff done during the week? Is Friday good for anything other than catching up on lost sleep? And perhaps most important, do your managers respect the off-Fridays or pull people in on a regular basis to handle "crises"?"