GREAT! Thanks John for that information. Now I know I can set my sights on buying the MTH DCS system in the near future. I assume the most current model is working well with no bugs in the system?
Jeff, the most current TIU is Ver.5.0.0 while the most current DCS system would be using MTH's DCS wifi module (WIU) connected to the TIU and then using MTH's Premium DCS wifi app (scheduled for release in March) to run your trains using either an Apple or android phone or tablet. Btw, that wifi module doesn't require internet service since although it can work with any existing household internet service, it will also provide its own solo wifi signal.
Furthermore, to simplify things even more you could eliminate your Cab1, Cab1L or Legacy controllers and just the DCS handhold to control all your TMCC, Legacy, DCS, and even conventional engines. To do that you connect your TMCC or Legacy base into the serial port of your TIU using the appropriate connecting cable sold by MTH.
The ultimate control, eliminating all handhold controllers including MTH's DCS one, would be connecting a MTH wifi WIU module directly into the usb port of the TIU and thereby operating all your engines with a smart phone or tablet using MTH's Premium DCS wifi app.
You can use your Z-4000 to power an y of the methods I've mentioned simply by connecting it to the TIU in the way already suggested by the previous posters.