The first four books contained a solid, workable formula. Two characters we genuinely cared about. I miss them, and I want more of them. Everyone I've ever talked to about the MYTH books feels the same. Secondary characters like Guido, Nunzio and Spyder, while they get a lot of play these days, just aren't grabbing us the way Aahz and Skeeve used to. They're one trick ponies, and the trick's been drilled to death, whereas I don't think the possibilities of the original characters have begun to exhaust themselves yet.
There's still potential here, but I can't help wishing a really decent editor would analyze this and come to the same conclusions the fans have.