Love love love this piece so much!!!!  I bought 2 for my office, and have one sitting horizontally, and the other vertically!  The variation in shapes of the cubbies are so fun and make my book collections look amazing!  
These shelves are SOLID WOOD, great quality, and pretty easy to put together.  There are lots of pieces, but the instructions are clear and concise.  A total win, I highly suggest it!!!!