Whether you are a Legacy fan or a DCS fan, both systems are based on old technology designed back in the 90's over fifteen years ago, upgraded over the years but basically the same. When it comes to the advances over that time technology wise it's the stone ages. Now we have Wifi for Legacy and coming soon for DCS but that's only a bridge. I submit to you the technology is there now to do away with the DCS system and the Legacy system. No need to be injecting signals to the track in the hopes that the what ever the reason due to the system in use the engine will pick up those signals and follow your commands. There's really no need to spend hundreds of dollars for one or both systems to run your trains.
Bachmman has it right, a bluetooth receiver in every engine connected straight to your tablet, or smart phone. No need for operating systems to connect to your layout. But Bluetooth is for the (I won't say cheap) inexpensive, basic way to run trains. Kind of like the running your trains with a ZW back in the old days.
What is possible today and I would bet not anymore expensive than what we have now is a Wifi module installed in every engine, operating accessory, etc etc. Get your wifi equipped engine connected to you home network and run your trains via your smart phone, tablet, computer and what have you. No need for operating systems and boy you have the starting of common operating standard in O gauge.
I've heard both MTH and Lionel say there system is the best, can do the most for you. Each was right at sometime but technology has passed you by. Will things change in the near future, not likely has both companies have invested heavily in their systems but we could be running our trains in a better way for less money.