I flew from Reno to Las Vegas via US Airways and had layovers in Phoenix for nearly two and a half hours both times. I remained in the same terminal I landed in, and I got a lot of walking in to see what was around me. I didn't take the tram or anything. There are a lot of dining options like people say on Yelp. Also, I got to meet some people on my flight from Phoenix back to Reno, so the slogan about a friendly airport is true.
The only inconvenience that I see is that if you are going from US Airways to Southwest in the same terminal, there is only one pedestrian bridge going from US Airways gates A and B to Southwest's gates. The good news is that I saw electric carts with passenger benches that were giving people rides, so I would take advantage of that if your layover is very short.