In hindsight I would say that The Weapon Shops of Isher was better than its sequel The Weapon Makers, even though it was very choppy from being a fix-up work of older short stories. It had better fantastic elements than the sequel.

There is a nice tip of the hat to E. R. Burroughs in the book. You remember when John Carter learned to walk on Mars with its low gravity, and keept jumping and falling unwillingly. Van Vogt shows a much more brutal variant: A score of men, newly arrived on Mars, have to walk over the surface to reach a station depot, cold biting into their skin, they can't handle the gravity, panic, run, and keep falling over and over onto the hard, sharply jagged ground, till they bruise and bleed, their eyes bulging like those of fear-stricken animals.