Nope Joe, operating older TMCC engines with the DCS control gets you TMCC performance. Remember, you're actually just using the DCS as a remote, the commands are being issued by the Lionel command base cabled to the DCS TIU.
As far as older Legacy vs. newer Legacy equipment, there have been continual updates in various aspects of the operation. One thing seems to have remained constant, the Odyssey II speed control and the 200 speed steps is the same from the early Legacy stuff to the latest. I have some pretty old Legacy locomotives, they have excellent speed control and the quilling whistle. Many of the newer Legacy models have better lighting controls, sequence control, etc. The packaging of the electronics has evolved over the years, early Legacy had packaging very similar to TMCC locomotives with the R4LC and the DCDS modules. The sounds were still the standard RailSounds power supply with an upgraded audio board. The new Legacy stuff has an all-in-one board that has a piggyback TMCC receiver. The board controls motors, smoke, lights, etc. RailSounds is not a single board.
