I've had a number bad experiences through Sky Harbor but mainly due to the airlines and delayed flights causing missed connections at Sky Harbor. The airport itself is decent. The biggest thing I believe to pay attention to is what terminal you come into and have to leave out of if you are coming through in a layover. The distance between the terminals is pretty long if you're in a rush. If your originating or finishing at PHX then everything seems to go pretty smooth. I do like the Blue Burrito for food and the renovations over the last several years have helped.
Another thing to note is the distance of the rental car center facility from the airport terminals. Make sure you add an additional 30 minutes for car pick up and 30 minutes for return on departure.