I actually love the concept. We were at Disney last week - after hearing about glow with the show, we wanted to change our plans to see a "GWTS" Fantasmic. I would have loved to go on the 15th, anniversary and first night, but we weren't able to switch our park plans, dining reservations, etc. We decided to attend on Friday, the 18th.
It was disappointing. I think that the ears are cool - but there were only a few of them dispersed throughout the theater. Oh, I am sure it was hundreds, but among thousands of people, it was difficult to get any effect. The 4 kids with us wore them, but there were not any in front of us, so the kids could not enjoy the effect. I heard the people behind us actually say - cool, that looks so neat! Maybe it will catch on with time - or maybe it won't. I guess we'll just need to wait and see.
I found myself looking away from the show the try to check out what the GWTS ears were doing, so they ended up being a distraction. If it was the first show when they were given away, I would think that the effect would be obvious.
We purchased the ears early in the day - but all of the kids found them too heavy to wear all day. And they will be heavy to pack for the return trip to Disney.