Asimov doesn't like Solaria.
There are several suggestions in this book that he doesn't like Solaria, and in other books he'll make it very clear by drawing the course of Solaria's history to end up creating beings with a (lack of) morality meant to horrify the reader.
In this book, Solaria is at its peak. It's already self-sustaining as far as I remember, though it hasn't cut ties yet with the other worlds. Each of its rare inhabitants are almost self-sufficient on their domains, as well, served by their thousands robots (since the technological level and civilization permits it), and habituated to their solitude so much that they no longer stand to meet their neighbors face-to-face.
I love Solaria, myself. It's a world of solitude, with interesting contraptions (hey, robots, whaddyawantmore), a world where you can pursue your life research unalienated by politics, funding, envy behind your back. You don't have to make a living, either, and human lifespan is extended, but these are characteristic common with other Spatial Worlds, only the first are not. And the first are what I love most about Solaria.
I've seen reviews saying that Solaria is a dystopian world, and that it's a "natural" dead end of humanity. I don't think so. I feel the nagging moralizing sense of the author interferes with the narrative, and there is an agenda behind his transparent condemnation of Solarian life from some social/political perspective.
To exemplify the nagging judgmental preaching. When you lead your life this way, in reclusive research, apparently you're no longer a pioneer, you don't take chances, your life is "unreal" or detached from reality. And The Solarian Way is doomed to fail. Seriously? I hope the conditions of present day research WILL go the Solarian route. That it won't continue to be stranded by politics, by the ugly side of human interaction under scarce resources, by academic rush for publish or perish and its short time to do things, by the forceful public involvement (be it conferences or a job to a Big Name Center or marketing your book) in order to merely gain access to research results relevant to your work.
I love The Solarian Way. I guess we forgot already about past centuries hermits, lone monks in their monastery, yer olde mad scientist in their laboratory. OK, I guess science can no longer be made by building yer own telescope or radio or combining herbs in your home lab. Which is exactly why I love The Solarian Way, it's them, the ideal home of the hermit, of the lone monk, of the mad scientist, in a setting of our not-that-terribly-far future.