This little unit looks to be a great alternative to the conventional buddy-box setup if you want to train people to fly -- but does it work "as advertised"?
The answer would seem to be "yes".
Aside from being a little large, the unit works exactly as claimed and will almost certainly become a valuable tool in teaching new fliers.
You could even use it as a method of handing over control of a model if you wanted to fly long distance -- using two pilots at different locations.