Simple properties are nearly always inlined, in my experience. But you're generally right about IEnumerable, for which the biggest culprit is LINQ. The problem

Simple properties are nearly always inlined, in my experience. But you're generally right about IEnumerable, for which the biggest culprit is LINQ. The problem is that the JIT doesn't inline across code which is referenced through a delegate, even though the actual method being invoked is the same each time. So code like "foo.Select(x => f1(x)).Where(x => f2(x)).Etc()" ends up making two function calls for every element in foo.