We've been turned away from Teppanyaki, Sci Fi, 50s Prime Time and Whispering Canyon.
We've had better luck with Marrakesh and Artists Point.
We made a 3:00 call to get 5:00 pm reservations at Spoodles, nothing was available later than 5:00.
Character meals always require a PS. Some people get lucky, but you don't want to spend all your time running from character meal to character meal trying to get value from your Gold Plan looking for a place to eat.
In fact, since you are on the Gold Plan, I'd make PSs for every meal. You can call Disney Dining from your room or a cell phone and change them on the fly as your mood changes, but for me, a sure way to ruin a vacation would be to pay big bucks for the Gold plan and end up eating counter service burgers because nothing sit down was open when I was hungry.