Let's not get all jumpy on the downvotes from a difference of opinion; a week may not work for you but for others... well we move fast.

The point was to encourage our fellow HN member to be open minded and try it for a short period of time. From there he can determine if the change has begun to yield any value or not.

And that advice is simply wrong. It's simply not possible for any team to reasonably assess the pros and cons of a given software development methodology - with the possible exception of the one they're already using - in a week.

Suggesting a team 'try a methodology for a week' is inviting a train-wreck.

Good to know you're the benchmark for productivity in the industry.

My own experience - across multiple teams, multiple organisations, multiple languages and frameworks - is that it can take weeks to evaluate even relatively slight changes to existing methodologies.

Let's say the OP decides to adopt Extreme Programming.

How long would you say that a team with zero experience in that methodology would take to get to the point where they're practising it well enough to perform a useful evaluation of the consequences?

Less time than it would take for you to realize that our experiences form only our perceptions, not universal law.