I went to 2 Spring Training games at his stadium this year, and had 2 different experiences. The first game we parked ourselves and passed several incompetent lot attendants just standing there. As there were no barricades and they made no indication otherwise, we assumed it was ok to pull in. It was only at this time that they waved their arms and said we had to park at the back of the lot. This happened 3 times.
The second trip we opted for the free shuttle from Zipps, This took the pain out of their incompetence out of the equation. Once we got in the park we had a great time both trips. There is ample shade covering a good portion of the seated area for afternoon games. Beer prices were a little steep, but we were happy to pay $8 for a pitcher or 2 of Blue Moon at Zipps beforehand to take the sting out of the $8 cups at the field.
Of all the stadiums I've visited in Phoenix, this one has been the best (aside from parking annoyances). It will be a challenge to top this facility.