I gotta go with Willie-O on the Grateful Dead comment. I've seen them in [relatively] small amphitheatres, huge stadiums, indoor arenas of various sizes and the sound was always at least comfortable and usually quite enjoyable, even in the big windy stadiums, like Soldier's Field and Rich Stadium.

On a personal note: I once had a tech with a Megadeth t-shirt and a stack of Motley Crue and Van Halen laminates around his neck ask where my bodhran plugged in. Words will only cheapen the rest of the story, but I can tell you that the soundboard tape we made did not turn out to be the great live demo we'd hoped for!

Rich