I think I read the corrected edition. The one that was published in 1952 was rushed out before his death and has errors.

I also have the Library of America version, but I liked this better because it was just all his poetry in order. It is bigger text and has more space then the Library of America verision - easier on the eyes.

Steven's poetry is like bookends - his first Harmonium and the his last The Rock. In the middle the full version of the Man with the Blue Guitar is also interesting.