I've had My System for about a year now, and I've finally come to the conclusion that the information in it, while groundbreaking when it was written almost a hundred years ago, has already been included in other books, and in a much easier to undertand format. I would only get the book if you had an interest in Nimzowitsch. You are better off with one of the contemporary authors, such as Silman, Pandolfini, or Seirawan.
P.S. My version is c.Quality Chess, 2007.
I am working my way through Amateur’s Mind and plan next to take a run at Nimzowitsch's My System. A handful of editions have been published and I am not sure which one I should get. I will certainly appreciate comments and recommendations on the merits of any version you have familiarity with.
Hank