I have a sinuous O-31 layout with all sorts of tight clearances. It has several O-31 switches from 4 to 63 years old. It also has four Lionel contemporary O-72 switches which are the devil's own. Rough riding is an understatement. So everything is run at slow to medium-fast speeds, more medium than fast.
There are many products i would like that are O-36. I pre-ordered the Lionel Legacy Wabash FM Trainmaster which was specified as O-31 in the catalog, but O-36 in many places of the product documentation. This loco, and a Weaver caboose oriented in one direction only, would not do a O-31 right curve into the turnout of a right-hand O-31 switch 3 passes in succession. I changed the curve to O-42 and all has been fine.
This experience leads me to ask if any of you are running O-36 products on O-31 layouts? I think this information might be of interest to more than myself. Answers are always appreciated.