With a PPO I can go to whatever specialist I want. With Kaiser you are stuck with the specialists Kaiser directly employes.
So if the Kaiser clinic by you is good then sure Kaiser is great. However if you ever want a second opinion or want to use a non Kaiser doctor your out of luck.
A PPO plan offers you freedom to choose what doctors you see. It will also enable you to go straight to a specialist without your general practitioners consent.
care to elaborate why?