The WAP is huge but there's a tram for most of it. There are two walking trails, one is 3/4 of a mile and one is over a mile. They're both cool trails but if you're planning on going in the summer, escondido gets HOT. you might have trouble walking with the steepness and the heat, that being said, the zoo is VERY steep, get the bus tour, as it gives you information on the animals.
If you're going to both, the membership mentioned above gives you two adult passes for a year plus two guest passes to both parks, but no train ride or skyfari for the 3rd person, but with the membership the bus costs 8.50 instead of 10 dollars and the skifari is about 3 or 3.50 each way, so if you add that up, i believe it's 126 + 8.50 + 7 (two ways on the skifari) that's not too bad comparing that to 3 adult tickets at 32.50 a piece for the zoo and i'm not sure but it's at least 20 dollars per adult at the WAP.
I think it's great entertainment for anyone, esp animal lovers. The cheetahs are fed by a truck at a specific time of day, i think maybe 1? You can ask at the front, but they're all the way at the end of the heart of africa walk (i think) and it's a trek, so don't show up at the front of the zoo at 1 and expect to see the cheetahs.
You CAN feed the giraffes, you can buy carrots or something for a dollar or too, but unfortunately feeding the cheetahs is not something you can do at the WAP, i've petted a cheetah, but i had to go all the way to a petting zoo in Mt. Kenya in the real Kenya to do it.
have fun it's a blast, I have to say that even though i've done a real safari i still love the zoo and the WAP