I have one, the Bond Girl Mini, which is their smallest model. It's a .357 magnum and I love it. Obviously they aren't super accurate at anything past "close quarters" but it's a derringer, it's not designed to be. It is more than accurate enough for what it's designed for. The hammer/trigger on the early models (like mine) are fairly heavy, not insanely heavy but heavy, however, those issues were fixed a few years ago with a redesign. You can send early models in to be retrofitted with the new parts if you wish, there is a small fee. The guns with the longer barrels and lighter triggers are obviously much more accurate than the ones most people on here are probably shooting. Bond Arms is now offering 6" barrels! They look crazy and I'm not a huge fan but I'm sure some folks will love them. I do plan to buy a barrel set in .45Colt/.410 with a 3-4" barrels one of these days for mine. I've had big tough guys at the range refuse to shoot mine and tell me I'm crazy for shooting a .357 magnum that small lol. It's not a pussycat but it's not a lion either, very comfortable to shoot in my opinion.
For what they are, they are awesome. The Bond Arms derringer is literally the Cadillac of derringers and has a very large fan base. If you want a derringer this the brand to buy. You can't compare derringers with other guns because there just isn't any comparison, it's the ultimate apples vs oranges comparison.