I think this is a bad comparison, because len() vs. foo.len() is just syntax, and isolated syntax at that. It's valuable to get syntax right, but this particula

I think this is a bad comparison, because len() vs. foo.len() is just syntax, and isolated syntax at that. It's valuable to get syntax right, but this particular decision doesn't really impact anything outside of itself. In contrast, the article suggests that the implementation of method dispatch slots (not __slots__!) actually constraints the optimizations you can make. I get that you're trying to suggest that they're both small, but I think that this analogy only serves to confuse things.