I find that the reaction to the bell depends on the bike I'm riding and the speed I'm riding. If I'm riding my upright bike with a front basket at or below 15mph, I ring my bell, smile, and do a little nod or wave. They usually pull off to the right, look at me, and smile/nod/wave back. When I'm on the road bike going 18mph+, I slow down to around 12-15mph and ring the bell a few seconds before passing, and do my smile/nod/wave, but if I'm in full kit, but they're less likely to smile/nod/wave back at me.
Probably just looks more intimidating to be in full cycling kit, where as I look much more approachable in my t-shirt and shorts when I'm riding the around-the-town bike.
I also make sure to ring my bell if I see dogs on the MUPs, and slow down much more than when I pass people. I also tend to wave to the dogs since I like dogs hahaha
I ride with a few people that think having a bell on my road bike is stupid, but I don't care, I use it often and I find it more friendly than yelling at people.