It is a good book, used as the requred text for the graduate soil mechanics class at UC Berkeley. I learned a lot from it. There are also other good references there, e.g. Soil Mechanics and Foundations by Muni Budhu.
If there were 6 stars to give...I would
Rating: 5/5
As a Geotechnical engineer in a graduate program I can honestly say that this is my most frequently consulted reference. More accessible and practical than Mitchell, or Taylor, (though not as theoretical or fundamental).
Holtz & Kovacs is a clear step above Das, Coduto, or Huang in scholarship.
This is a book that you keep for your engineering career.
Best book for understanding
Rating: 5/5
However you still need Braja M. Das for your PE Exam Good Luck