We used them in early November 2004. I scheduled "Tigger's Bouncing Day" at Epcot for my daughters who were 10 and 5. We thought it was a real unique event and my girls really seemed to enjoy it.
My only issue was that the event was scheduled to begin at the end of our scheduled PSB breakfast in Norway, and we were to be presented with a letter when breakfast was complete. Of course we finished breakfast quicker than anticipated (they really rush you through). At the end of breakfast we hadn't received our first "clue". We stalled in the restaurant then just kind of hung around the Norway pavillion. I finally received a cell phone call from the pixie and we made another plan to start our event. Everything turned out ok, but we had some real tense moments, especially for this "Type A" personality.