> Creating an object and creating a closure both need to allocate memory in the VM, but the closure doesn't need to expose its internals the way an object does and therefore can be further optimized by the runtime.
Actually... creating an object instance via a constructor lets the runtime use an internal class, which improves performance (as long as you don't modify its properties post-construction). This is a well-known aspect of V8 performance.
Even with an internal class you're still doing lookups for properties. A closure can instead use local variables which are accessed by index. Why do you think its good practice to pull properties out of objects and into local variables before a tight loop?
Actually... creating an object instance via a constructor lets the runtime use an internal class, which improves performance (as long as you don't modify its properties post-construction). This is a well-known aspect of V8 performance.