[jjarvis]

This! I am fortunate enough to belong to a small team which has mostly adopted Basecamp's "shape up" method and it has been a breath of fresh air.

I think the biggest game changer is the notion of using the "appetite" (number of weeks per cycle) to drive the design of the solution. This is opposed to the usual approach of coming up with a solution and then estimating the points/time it will take to do each part of the project. SE's are bad estimators and the product manager rarely uses time as a design constraint. This is why most projects run past their deadlines IMO.