I've tested this a few times locally, with a set test case of 20 workers building a dropside, then going to mine stone. Overall, there's an improvement in how fast they find a valid path, and get to their destination... which I believe will lead to a performance increase overall; because if they get where they're going faster, they'll spend less time computing how to get there.
Beyond that, it may be worth while to test it in a game ... which I'll likely do soon.