They initially had the model in the trailer for people to use, but then transitioned to walking around the site with laptops and tablet PCs. On one project, to communicate the location of ductwork, they actually spray painted the duct locations on the under side of slab in yellow. I assume that they precisely located that using a model to Total Station workflow.
I actually really like that method – we’ve used the model to lay out wall partitions and penetrations on the top of slab, but we haven’t done anything on the ceiling. This sounds like something that would make sense for us to use on the Crate&Barrel, where things like lighting fixture placement is so critical.