I did give it a go and was pleasantly surprised. Scored one panel I was hoping for.
How it works, you sign in. Then it’s an open marketplace. If anyone offloads their reservations they will appear there that you can then take. I’ve seen everything from signings to panels to experiences. That said it seems those with lower reservations, 1-2 seem to have higher proabability. Probabaly didn’t help that
D23 let people book up to 7 guests. Lol
The key is being quick and fast to book as they go quickly. Then periodically refresh to see what’s available.
I think this is a great aid and can be helpful to get people into what people wanted. I’d check it periodically even while at the expo.