Anecdotally, it has streamlined my thinking process exponentially, and made me more self-aware. However, most proponents of most belief systems will make similar claims.
Our general techniques of using science to come to truth is inarguably valuable, but that’s not unique to us.
What evidence can I show to a non-Rationalist that our particular movement (i.e. our particular techniques for overcoming biases, studying decision theory, applying Bayesianism, learning CBT techniques, etc.) is valuable for making their lives significantly better?