Thank you Yelp for my first opportunity to enjoy Gammage.

Impressive architecture and design (it is also mostly functional)!  
The seats are roomier than expected and the rows have just enough room between them to allow people to pass relatively easily in front of you without having to stand up to let them through.[Relative to US Airways Center seats which outside of Lexus Club and courtside seats are several inches narrower than the ones at Gammage and you have to stand up every time someone needs to pass.]
Having the room to pass easily is nice, especially if you are seated in the middle of the auditorium, since you have to pass in front of at least 30 people just to get to your seat if your, say, running late or need to escape to the restroom.  
This is also a negative especially if you are the crowd-fearing  or clostrophobic type, there are not good "outs" from the center.  

I think it is wonderful to have a location that hosts wonderful Broadway performances and a variety of other artistic entertainment/performances.