I was impressed with the quality of cedar wood provided with this pergola.  Instructions were easy to follow along with pictorial illustrations of how each part fits together.  There were a couple of pre-drilled holes that required additional drilling to allow for a perfect fit. However, most of the pre-drilled holes were perfectly made to allow for easy assembly.  Product was received inless than 7 days allowing me to assemble before an event requiring my patio. 
Please note that the dimensions of the Pergola are not from pillar to pillar but from rafter end to fafter end which extend beyond the pillar.  I do recommend this product for purchase given its make, look and size if it matches your needs.  Thanks Wayfair!!!