They have looked at double-crewing the crews on board and various things. There are some practical applications, as with anything that flies.
Conceptually, they are designed to be able to do short-lift vertical takeoff, and some of them are designed to do long-haul. It just depends what the application is.
A lot of companies I've chatted with have said many times over what Barry has commented on—namely, if you bring it to the marketplace and prove that it works, we'll use it, but we're not going to spend any money on R and D to get you to develop your machine at our expense.