The PECO turnouts are far better than the Atlas ones but I am starting to see several Bachmann steam engines derailing at the points and frogs. The Bachmann engine front trucks AND TENDER TRUCKS SEEM TO BE SENSITIVE HERE.
Bachmann engines seem very light and have little engine front and rear truck downforce. Their tenders are also light.
DMK
The flangeways of the guard rails and frogs of most commercial switches are too wide, allowing wheels to go places they shouldn't. A bit of strip styrene can be glued in place to narrow the gap, so the wheels are guided better. Point picking can usually be fixed by filing the point ends to lie closer to the fixed rail.
Len