The only disadvantages I've ever heard about moon clips are the same ones I've heard about speedloaders . . . they can be awkward to carry and it takes a lot of practice to achieve speed and surety with them. Other than that, modern moon clips have been around since the end of WWI for a reason. And if there's one thing I'm sure of, it's that you Dave can and will take the time to achieve speed and surety with them if you make up your mind to do that.