Not much detailed information on the Fleishmann Roco Z21 system, but it does appear to offer Cab View operation with realistic control functions.  This would be like combining a railroad computer game with a model railroad.  The demonstration video shows a virtual cab interior with a video cab camera view of the model railroad.  Control would be by touching the controls on the virtual cab screen.  All this would be displayed on your choice of wireless device... smart phone, i-pad, etc.  Perhaps the desk-top control stand such as used with computer games could also be used.  Steam controls might also be modeled.  The Z21 is not tied to a proprietary control.

An interesting operating challenge is the old Espee line between Gerber and Dunsmuir.  This is undulating territory with spectacular bridges on the Shasta Dam relocation.  The cab-forward steam locomotives would offer the ideal Cab View.  Steam (no dynamic brake) and caboose operation would challenge train handling and air brake skills.