I do not see S as stagnant. We certainly do not have the variety that exists in full scale O gauge but there is plenty of scale sized and reasonably detailed equipment available. I have 30 TMCC/Legacy engines on my layout. More than I can operate in a week. There are six in the above picture and six more plus an original Gilbert 342AC in the picture above that. Five more in the first picture. Whether the cars are from Gilbert, Lionel, SHS, MTH or AM they are all scale proportioned and intermix perfectly. We always want more but what we have is pretty nice.