O.K. This is the first time I am saying this on these boards...at my house we say PS stands for :
P retty S oon you'll be
P romptly Seated...and if you believe that you are
P retty S tupid!
As you can imagine, we had a bit of time on our hands waiting for our PS at Sci Fi for DS birhtday. I had made the PS a month in advance for 7 p.m. explaining it was a bday dinner, explained that again at check-in... waited 55 minutes for our PS, we were getting pretty darn hungry now that it was almost 8 p.m. (this was the first week of August) no happy birthday, etc. When we sang to our son on our own, our waitress came by and said, Oh, if you had told the desk it was a birthday I would have had a few goodies for your son!

We had a blast there tho, food was really good, kids loved the car/drive in thing. Luckily DS did n't know that we had tried to arrange a birthday deal, he just enjoyed it. It was worth the wait, but I know what you mean, it can be frustrating.
However...this time we are going over Christmas, and you betcha I made PS's! And I will be grateful that I did!
I hope you are able to try the places you like, I think it is a great idea to try desserts out at places. Heck, we go for dessert at places at home here, why not at WDW?
Pam