Putting is so much feel, so it's hard to tell if a belly putter will work for someone. But if you're having trouble with short putts, it's going to help you regain your mechanics so that you release the blade through the putt. If nothing else, in that way it's a good training device.
I used one for about two years, and when I went back to a conventional putter last year, I found that I regained my stroke, especially on shorter putts, as a result of using the belly putter.