As strength of Kuttner and Moore's story is that they make no attempt to argue that their 'sideways in time' mechanism is innovative. In fact, there's barely a mechanism at all - just unexplained Earth Gates of an alternate technology. Instead, the story is all about the personal - an actor facing trouble who falls by chance through a portal to a world he though his uncle had invented. The protagonist is an everyman - definitely and defiantly not a hero, just stumbling through as best he can, doing the things we might do, though with a little more knowledge of the inner workings of a television than most. Overall, he's appealing.
Despite Moore's participation, it's definitely a men's story - not in a macho sense, but because the only woman in the story has a very thin part to play. It's a world of men, and a story about men. With that as a given, it works fairly well. The ending does descend into trite sterotypes, but at least does so knowingly and sardonically. Overall, it's an interesting light adventure piece that won't change your life.