You make a really good point on the importance of having a complete iteration at the end of the sprint. In my experience, the fixed time increments have always

You make a really good point on the importance of having a complete iteration at the end of the sprint. In my experience, the fixed time increments have always felt too constraining. I think a team can accomplish a similar goal of having regular incremental progress in the form of complete systems by relaxing the fixed-length sprints requirement. The alternative that I favor is Kanban with defined releases. A release, as a collection of features, is a complete system, but it doesn't necessarily have to be finished in the same time that the previous release was. A larger release may take six weeks instead of the smaller previous release that only took one. You make a lot of good points, thank you for sharing your thoughts.