Interestingly, the 2nd argument to Object.create was specifically designed (by me) so that an object's "shape" could be statically determined. If the descriptor is all literals (they usually are) then each Object.create call site is essentially a construction site for a "class" of objects that share a common structure.

As Erik says, this should be fixable. It sounds to me like Crock's coding style is just ahead of the engine implementation curve. Hopefully it will help push this optimization into the actual implementations.