They work but they can be a pain to keep in good operating condition when the fish are really biting. Fighting a fish tends to get the wire bent, and even a small bend can keep the prop from spinning freely. Plugs with props in the front and rear are particularly finicky like that.
The first picture is a plug that's still in my bag, works well but I've no plans on making more.
The second picture is of a newer design. The props on a separate bit of very heavy wire avoids a lot of the bent wire binding problems that occur on the plugs where the props and the hooks are on the same through wire. These I still make.