Coming to O scale from HO myself, I find the smaller DCS systems useful. I do own a Rev L DCS System and intend to add on as my railroad grows. The biggest change I can see is bringing Lionel Engines into the picture.
Forum Members have been very gracious with sales, trades and advice. If these forums did not exist, I would have been lost moving from O scale conventional to binary control of engines.
There isn't much to stop you from running a single engine as you learn. When you reach a certain point in your journey in DCS, you will move into bigger and more capable systems. (And add engines too I bet.)
Good luck!
