I visited the palace a few weeks ago for the first time and found it to be absolutely gorgoeus. Although there were bums, they did not bother us at all.The deteriorating statues and old architecture is exactly what gives it it's character.It was free and easy to get to using public transportation. The exploratorium, next door, I found to be overpriced and more for children. The palace is a must see..atleast once! And if you walk across the street, you have a great view of the golden gate bridge.
Pros: beutiful view, free, easy to get to
Cons: not much else to do