Thanks for posting the video. I've been chomping at the bit since Lionel announced these models, desperately figuring out how I can pay for one.
I hate to be a rivet counter, or in this case a boiler counter, but this is yet another steamer model with the underside of the boiler extending downward into what should be open space and the suspension, including leaf springs. Lionel has used this un-prototypical U-shaped boiler casting on so many of its scale models. My scale Lionel Berks, Pacific, and Mountains all have this type of casting, whereas the newer releases of the Reading T1 and Milw. Rd. S-3s have rounded and prototypically correct shaped boilers.
I suppose the prototypical accurateness of the bottom of the boiler becomes a moot point when you're running trains and standing above the models such that you don't notice the underside...but from my outlook these are expensive scale models, and modeling a steam locomotive should capture the essence of the machine - of which the boiler shape and suspension are a great part of IMO.