I think the take-away from this article isn't that you should absolutely use the 4-1/2 day workweek model at your firm; instead, I read it to say that they had

I think the take-away from this article isn't that you should absolutely use the 4-1/2 day workweek model at your firm; instead, I read it to say that they had experimented with several different schedules, put some serious thought into what worked and what didn't, and then implemented a solution which was tailored to their team, deployment schedule, and customer base. If you want something which works as well in your business, don't just mindlessly clone this, or the 37signals 4-day week, or the first-stage startup 80-hour deathmarch, or any existing schedule -- work it out for your own environment. Personally, I've been doing a lot of tweaking of my own schedule at work over the last year, and found that having at least one full day a week where work from home is a big booster to my productivity. It's an entire day where I can avoid random interruptions, and I never have that meeting in the middle of the morning that basically wastes the day through lunchtime.