It has become apparent that Lionel is in the process of establishing two product lines for their S gauge trains. The AF based trains have been around since the first three freight cars were unveiled in 1979.
The new stuff is an attempt at establishing an S scale line and owes little or nothing to the previous A F designs. I think the U-33 Cs I just bought are wonderful examples of this. Putting Legacy in the new diesels seems to be a big step toward establishing it as a command control standard for Lionel S scale trains. It is a more advanced system than DCC and much less "geeky" to use in my opinion.
The new solid "T" rail FasTrack is also a welcome addition to the Line.
Ed Boyle