Experiences with the Shape Up process

I run a small software team where we have been experimenting with the Shape Up process developed by the people at Basecamp. We've only ran a handful of projects with them, and it's been a interesting ride so far. All of our projects have been huge successes from the business perspective, but I'd be lying if we didn't run into some roadbumps along the way.

If you have not heard about Shape Up before, I highly recommend at least reading through some of the introductory pages of the process (or the whole book - its freely available online). The basic idea of the process is that you spend a lot of time "shaping up" brand new projects by spending time researching, thinking of the basic elements of a new feature, the impact on the business or customer, and de-risking any particularly gnarly technical questions up front and in an asynchronous manner from teams actually performing project work. Finally, the team that will execute the project receives a fully-baked idea that gives them plenty of creative wiggle room to make meaningful decisions on how the idea will become a reality. The project team does this by having full control over scope, and being given the time to explore different ways to achieve the project as long as the project is executed within a fixed timeline (by default 6 weeks).

I'm interested to hear if anyone else is experimenting with this process, and what their experiences have been so far. For my team, it's allowed us to bite of projects that would have been extremely difficult to execute via a scrum. I suspect that the main reason behind this is the acceptance that engineers will not truly understand the scope of a problem until they start to get their hands dirty. By allowing engineers to have this discovery time baked into the process, as well as giving the project team the power to respond to discovered additional work by having control over the overall scope of the project has been a game changer for us.

So - is anyone else using the Shape Up method? Does it sound interesting? What are your thoughts?