I've used mine plenty, both on a MUP and on quiet city streets in the morning when I'm out doing my morning ride. There are plenty of morning walkers who I used to surprise when I came up behind them, until I got the bell to alert them of my presence. A few of them have even thanked me for the heads up. So I will continue to use it.

But yes, it is a bell and not a car horn or fire truck siren. It has limited volume, but in my particular case it's plenty loud enough to be noticed.