Gammage is a great spot to watch plays! Watched Bodyguard and it was a great play. The facilities here though are getting a little old, carpet, seats, flooring, surroundings are dated. I'd imagine most of it is original.
They do have wine, beer and cocktails along with some snacks which is a definite plus. Would recommend showing up at least 45 minutes early to park, find your seats and grab a beverage.