If not for noise, list() should always outperform copy() as copy() just calls list() internally (specifically type(l)(l)), and also incurs the cost of several interrupted function calls.
Also, the minor difference in slice vs. list() for large lists are likely platform dependent and highly sensitive to the details of branch prediction and cache.
Also, the minor difference in slice vs. list() for large lists are likely platform dependent and highly sensitive to the details of branch prediction and cache.