These are novelty guns (i.e. a fad) that do 2 things.....neither of them particularly well. In the end what you have is a large, relatively heavy pistol that's not particulary suited for concealed carry and isn't very good for self defense when compared to other pistols.
If you want to have fun shooting pumpkins and plastic water jugs then by all means - pick one up. If you spend a lot of time out on the farm or ranch and have to deal with poisonous snakes and assorted varmints then this is the gun for you. If you want to carry something concealed for defense against 2-legged threats....there are about a gazillion better pistols to choose from.