Full disclosure, I have never been a guest at the dessert party, but I have attended countless times.
I'm sensing that some of you may be needlessly stressing out about being able to get a rez for the SW dessert party. Attending the dessert party is not the end all for having a great SWaGS experience. You can have a great time without attending the party, the vast majority of guests that are there for the show do just that every night.
If you arrive at the Center Stage area at the same time you would have arrived at the dessert party, pick up whatever food and drinks you like, I guarantee that you'll get a great spot. And in many cases, just as good as the VIP viewing area, you'll be just fine. You'll save a ton of money and IMO, it can be more fun. And depending on how busy the park is, you may not have to arrive that early.