My brother saw The Dead at the old Boston Garden - IIRC, that was the last show therebefore they tore it down. He was at midcourt, eye level with Jerry's guitar. Said it was great.
My parents were at the same show - as chauffeurs and my dad was a deadhead from way back - not to the extent of following them, but deep appreciation.
They said the clouds up there were so thick they had trouble seeing the stage.