When a C# programmer sees any call to code they don't know - property or function - they should know its complexity is O(?) and will (hopefully) vet it before calling it in a tight performance sensitive loop.

I get that someone could say "Go has fields, and they're always fast" and that seems like a great facility of the language, but any C# developer that says similar about instance members is wrong, and has some invalid assumptions about the language they use.