I have two main points to make about play:
A) The linguistic style used in the play (I read an English translation of the work) is inspired by that of Shakespeare and almost as beautiful. There's almost nothing authentic about the structure of plot (a beginning, a downward trajectory of the hero, then the redeeming denouement). The theatrical form is also non-conventional (the writer writes a sort of apology for it at the start, maybe in a hope to avoid criticism on that part) and finally, the play is meant to be a "closet drama."
B) The content of the play (how characters develop and what actions they do) is also nothing new for the 21st century reader, and the significant time gap between the author and us is also another matter of importance. However, within the larger context in which the work is produced, it is almost quintessential. How? Well, the concept of "glorified thieves" had almost gained a historical consistency by that time, something reflected in the theater, as well. So this play is one of the best ones written on that matter.
For more information on the concept, you can read "Extraordinary Delusions and Madness of Crowds" by Charles MacKay, Chapter 14.
P.S. The brothers have different names in different versions. In my version, they were Francis and Charles, while in some others they are Franz and Karl, respectively.