This is a great thread, Its making me examine some of my work practises and suggest alernitives. I am mainly doing corp stuff now and its a horses for courses approach, what seems best for the day. Usually a split mix to camera and iso's separately . Recently did a short film in a large reverberant hall with talent lav hidden in a lace ruff. In the wides the lavs would be too clean so the boom track would smooth that out , never thought of it as an ambience mic or pointing it away from action.