I do not know the Tractive Effort Each of the Monster Engines Have, but, I really like the Added Effects on the VisionLine Challenger, and the recent VisionLine Big Boy. The Whistle/Steam Effects, The Echo Effect, the Dynamo, the Blow Down, The Cylinder Steam Effect, Yes, The Depleting Coal, and of Course, Legacy Controlled. To some, the wheel slippage may be liked, to others, maybe not. In my way of thinking, Lionel could make this for less money as they have the moulds. All that's necessary is the Electronics.
Yes, This would be a nice Fun to Run Locomotive. Good Thread.
IF Lionel Chooses to do this, my only Major Suggestion, Go back to the system for the Blow Down that was used in the 0-8-8-0 Pensy Mogul, or the 2-10-10-2 Sante Fe 3000.
Those engines have a great Blow Down.
Happy Railroading......