Clearly there were some major regulatory hurdles they were working through related to licensing and other FAA requirements, but (according to the CEO) they had customers ready to buy and start using them.
The new TF-X model looks a lot slicker, and uses computer-assisted VTOL: https://www.youtube.com/watch?v=wHJTZ7k0BXU
Curious to see how this plays out under new ownership.