There's nothing the matter with it. It's an unusual design but works fine and reliably. The only problem is a relative lack of off-the-shelf cam grind options. If you want a better-than-stock cam, you need to do some extra work in specifying the grind with a competent cam grinder, after talking to highly experienced experts like Doug "Doctor Dodge" Dutra over on slantsix.org .
If they have any advantages (except the fact that they only have to be adjusted once) I don't know what it is....