Luigi is nice, because it is really simple to get started and it gradually allows you to do more complex things like (custom) parameter types, custom targets, enhanced super classes and dynamic dependencies, event hooks, task history and more.
One thing that I missed a bit was automatic task output naming based on the parameters of a task, so I wrote a thin wrapper for that [1]. This helps, but mostly for smaller deployments.
Airflow and luigi seemed to me like two side of the same thing: fixed graphs vs data flow. One fixates the DAG, the other puts more emphasis on composition.
That said, I am excited about the data processing tools to come - I believe this is an exciting space and choosing or writing the right tool can make a real difference between a messy data landscape and an agile part of business and business development.