I bought this new (Michael Hoffmann) translation after reading Dustin Illingworth's enthusiastic review in the New Yorker. Most of the reviews on Goodreads and Amazon are of earlier translations. Hoffmann is a poet and highly regarded translator of some really interesting German literature, including Ernst Jünger's "Storm of Steel" and Hans Fallada's "Every Man Dies Alone." So while the other translations may be adequate or even good, I'd recommend Hoffmann's.
I really wanted to like this book, and loved the beginning, where upstanding citizen and horse dealer Michael Kohlhaas is shaken down by a nobleman whose property he's traversing and is transformed into a terrorist. But after Kohlhaas meets Martin Luther and negotiates an order of protection so that he can seek redress in other jurisdictions, the book becomes quite confusing. Kleist's intent may have been to create the type of disorientation that Kohlhass himself experiences as he attempts to navigate the chaos of competing authorities, but I felt frustrated by my unfamiliarity with the legal apparatus of 16th century Prussia and had trouble following parts of the narrative. Then, close to the end, a gypsy/witch makes an appearance and turns the story in a really surreal direction. I wasn't sure what to make of that either.
The book is only 112 pages long and the action is non-stop, so you can power through the rough spots without too much aggravation. The reward is a trip to a distant time and place that deals with issues of eternal significance: rebellion and the pursuit of justice.