After attending the MTH session at the NASG convention, I decided to add DCS to my Legacy controlled layout and to buy one of the F3's. Now I can run Legacy, TMCC and DCS engines from my smart phone or tablet using the MTH premium app.
The app is very good and gives you access to nearly all Legacy functions. In fact, I haven't figured out any that I can't do yet.
I have wanted to add wifi controls for a while, so I was excited to learn I could add one control interface that would allow me to run both Lionel and MTH engines even if its only F3's for now (not to mention all of my ERR TMCC modified locos).
If anyone is interested, I can tell you what you need to buy and how to hook it up. The addendum on this topic available on the MTH web page will tell you most of what you need to know, but I did talk to one of the MTH experts to make sure before I purchased anything.