While better than the other Knight that I've read (Hell's Pavement), A For Anything still leaves a lot to be desired and leaves me feeling like I can safely pass up anything else written by Knight in the future, especially since most consider this his best work.
The narrative is far more coherently drawn than Hell's Pavement, though we still have a dystopia that was nucleated by a singular macguffin technology. In A For Anything the macguffin is a simple matter duplicator called a "Gismo" that gets spread to the public, prompting widespread societal upheaval. The story takes place some generations after this event, when the control of this device has been taken over by an aristocratic class who rule over a much large slave caste, much of whom have been 'duped' by the device itself, clones that get replaced as they age out of their function. The central character, Dick Jones, is the juvenile heir apparent to a feudal lord who rules over a portion of land near Pittsburgh. Much like the aristocratic class in Vance's The Last Castle, Dick and his family are mostly wrapped up in political intrigue games, focused on concepts like honor and tradition as their every whim is serviced by the slaves that serve as the backbone of society. Dick is sent off to Eagles, the capital city located near Denver, to earn his stripes in society, make connections with other nobles, and become worthy of inheriting his fathers estate. During this time at Eagles, Dick is involved in political subterfuge that eventually gets overshadowed by a widespread slave revolt.
The central thematic idea is that, once material goods becomes unlimited in quantity, the dominant commodity will become labor itself, and wealth will subsequently be measured by how much labor you command. Hence, a slavery caste system. Knight certainly has a pessimistic view. Where others might see a utopia, he sees reason to believe that without the struggle to survive we would find ourselves reverting to some of our most sinful tendencies as a species. I find it hard to agree with him in many ways.
The characters, the setting, the prose, and everything else outside of the central idea and narrative are boilerplate at best. Nothing memorable or exciting that would set it apart from the million other dullard dystopian novels of the time period. The Last Castle is its superior in most every way, so it's hard to get excited about the limited strengths that I found here. It's also rife with a lot of the more regrettable gender and racial stereotypes that were common at the time.
Interesting to a point, but ultimately not super noteworthy in any particular way.