I have been going to the Phoenix Zoo since the 1970's and the transformations it has seen have been wonderful! In the past few months they have completely renovated the Orangutan exhibit and built a nicely appointed building for events on-site. Many of the animal enclosures have undergone renovation and there is very little of the old 'cage' mentality.
They are very kid friendly at PhxZoo with many programs designed for kids - like Boo at the Zoo, Fisher Price Discovery Farm, Stingray Bay, the Children's Trail and many more, day and night. Events also exist for adults and families and can change by the season - Zoolights is a wonderful winter holiday experience that goes on for a month or so.
The Phoenix Zoo is also actively involved with conservation efforts (Arabian oryx, Mexican wolves, African Wild Dogs), sanctuary (White Rhinocerous, Bali mynah) and rescue and rehab (California condors, the 3 elephants).
While the zoo is about medium sized, there is a safari train or if you prefer, good walking paths. The zoo has several specialized areas - such as the Arizona Trail, or, my favorite, the South American Tropics Trail.
All in all, there is something for everyone here. Highly recommend Spring, Fall or Winter visits. Summers are awfully hot.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.