Jonathon, I think I have a similar perspective to yours. I plan to order a new Y3. The prices had to go up close to the O gauge engines to be viable. I would buy any of the engines you list if Lionel makes them.
My biggest gripe with the Lionel S gauge engines is except for the Big Boy, none of them have the O gauge absolute speed step boards. The 200 steps in S gauge are relative, and each engine model seems to be a very distant relative of the others. Some examples, speed step 15 on my Challengers gives the same speed as speed step 60 on the Big Boy. Speed step 15 on my older E-L U33 is the same speed as speed step 45 on my new Santa Fe U33. It is impossible to do a lash up unless the two engines are the same model from the same production run. For $1,800 I would expect Lionel to make these run as the O gauge engines do.
