StructOpt v0.2.0 is out. You can see the changelog for more details and how to migrate.
After exactly one year, I think that StructOpt is really featureful. All the important lacking features are implemented, most of the time by external contributors.
I want to thanks all the persons that helped structopt, as the contributors, the persons opening issues, the clap authors, the persons promoting structopt and all the users.