I've owned Bond derringers. They are strong, heavy, well made toys. I wouldn't consider one for serious carry. Problem is that they are rather difficult to cock and the trigger pull is very heavy. That would make it a slow gun to get into action and once in action the trigger wouldn't help accuracy at much greater than arms length. Another consideration is that using defensive ammunition, the gun would be very difficult to control and a second shot would be mighty slow in coming. Finally, you have only two shots. Why settle for two when you could have 5 to 10 and less weight?
I bought my Bond to use in Cowboy side matches. It is great for that function. If you have rats in the barn, it might be useful. If your wood lot is infested with rattlesnakes, it would be a comfort. But for defensive carry, not so much. YMMV.