Actually, pop seems to perform at the same right, so either I'm doing something wrong in my test (likely), or V8 in browsers != V8 in nodejs, or at least the versions are different as of Feb '13 [1] in comparison to nodejs 0.10.17

[1] http://stackoverflow.com/questions/8423493/what-is-the-performance-of-objects-arrays-in-javascript-specifically-for-googl