I did this working for the Canadian GVT for about 3 years. I loved it, but I took Mondays off instead of the Friday, because there was already too many people taking the Fridays.

If you break it between the beginning and the end of your shift, you barely notice it.

In the office that I worked in, everyone worked 8am - 4pm. People working "compressed hours" or the 9/80 as you call it, could come in either an hour before, or stay an hour later to get in the extra time.

Instead of doing that, I chose to start @ 7:30, and leave @ 4:30. Barely notice the difference in the shift, and you get an extra day off every second week.

And as was mentioned above, if the holiday fell on the Monday, I would then take the Tuesday off and have a 4 day week-end.

The only thing that screws with you when there is a holiday on your day off, is that if you DO take the Tuesday off, you're taking a day that you would normally be working 9 hours, but you are only getting paid for a normal shift, not an extended shift. SO that means that you are down and hour and you have to make it up somewhere else, so tack that on to an already extended day.

That part always annoyed the shit out of me.