A little to add on GGG's post above:
Basically you are discounting the capability of the technology based on it's current implementation. When it comes down to it yes, as it is currently offered, legacy is better for a whole railroad, and LC runs single engines, however, that is not because the tech can't handle it, but because the marketing is better to not to cut into an expensive system you are trying to push. There is no upside to cutting into your own market that has fiercely loyal customers. Had Lionel wanted to, they could replace the track signal in Legacy with the same 2.4GHz transceivers used in LionChief, and kept the system otherwise identical but without the problems of a track signal. As far as cost, currently there is no practical difference between a 455K and 2.4GHz board, though for a one off hobbyist, the 2.4 is easier to find and much cheaper. ( $1.50 vs. about $5.00) other than the device used to transmit and receive the radio signal all of the other electronics are identical. In the end, i'm sure someone made the call that if it wasn't broken, why fix it, however I would be very surprised if the next generation control system doesn't use 2.4GHz or 5Ghz radio. Implementation for backwards compatibility could be easily accomplished in two ways. To give the most access to features you would pop out the R2LC(or Legacy equal) and replace with a new module that receives commands directly from the new base, or the second option would be a module that connects to the track and relays commands over the 455k track signal.
Also as far as two way communication, this is built in to mass produced 2.4Ghz modules and takes the same amount of code to turn off as to use.
Guess the point of all this is, the LC+ tech is not in any way inferior to that used in Legacy/tmcc, it is just specifically designed not to compete at this time.
