They can be fun and entertaining, but IMO do not last nearly long enough to warrant the difficulty in finding them to participate.
If your in town and just happen to be in the right place at the right time, very cool.
But it is a hassle to keep trying to find them to keep 're-participating' in the same 5-7 minute scenematic "rpg" event.
Is this not somewhat the same script/rpg event that took place a few months ago?
I do recommend all that have not done so to check it out at least once and absolutely try to have fun with it.