All Lionel "Lionmaster" locomotives especially the Big Boy and Challengers are semi-scale and look good pulling traditional size and scale cars because they are so massive. In my opinion, they look good parked next to other scale locomotives and only look small if you park them next to a scale Big Boy, Allegheny, or Challenger. If you don't own the scale counter parts, no one will ever notice except the rivet counters. They came in TMCC, Legacy, and the latest ones are now Lion Chief Plus (comes with a plastic remote). The reason they can all do O31 is the rear drivers are articulated like the front drivers. On the scale locomotives, the rear drivers are fixed to the frame just like the prototypes.
Does the locomotive look "silly" on O31 curves? IMHO, "A little" as that's very tight, but put your curves in a tunnel or block them behind scenery and no one will notice if that matters. Opening up to wider curves if you can makes it look amazing!
By the way, go to my Paul's Trains youtube channel in the layouts playlist and you will see my Lionel Legacy Big Boy in action going around on O42 curves on the outside track and O36 curves on the inside track.
