"DCS is still being supported, they spun that off to a small group of employees, so DCS will go on, if someone wants to use it. "
Maybe.
For HO, no doubt, it would be DCC I would strongly consider. As far as I know, all MTH HO locos can function with DCC. Not always perfectly, and all features, but DCC is guaranteed to be around 1, 2, 5 and probably 10-20 years from now. Just worth considering.