I think it’s almost always less productive. I suspect the reason software engineers like to talk about how productive it is, is because software engineers tend to enjoy sitting down and their own code the way the want to do it. Collaboration, teamwork, and anything that involves accounting for the needs of other stakeholders all gets in the way of that. So you can feel more productive, because you get to spend more time doing the things that you think of as productive. But really you’re probably operating much less efficiently from an organisational standpoint.