This is a good bookcase, but I had trouble with the assembly.  I have assembled many furniture pieces, so I was able to make the adjustments needed.  I purchased two of these and had the identical problems with both.
First, the many holes which receive the shelf pegs were too small.  I had to ream them out for the pegs to fit. 
 
Second, the bottom fixed shelf was 18” too deep, so the cabinet back piece wouldn’t lay flat without planing that shelf down by the 18”. 
 
Third, the dowel holes on two of the pieces which were to join were off by 18”, so to be able to join them, I had to whittle one of the dowels down with a box knife until they fit.    

These cabinets do have a very nice look, the paint finish seems good and all but the back piece is made of solid wood.  Solid wood shelves are WAY less prone to sagging than 
particleboard in the long run.